Original Link: https://www.anandtech.com/show/766
Although they may not be the largest x86 processor manufacturer on the block, they are definitely the favorite of quite a few in the enthusiast community these days. Their recent burst in popularity is not without merit. The launch of the Athlon microprocessor close to two years ago has truly brought desktop performance to new levels. It is clear that the Pentium III architecture is an aging one, so the Athlon's original competitor is now on its way out of the picture. What AMD does have to worry about is the Athlon's latest bully, the Pentium 4.
From a purely architectural standpoint, the Pentium 4 is quite impressive. Its performance in today's applications is disappointing but judging by its performance in upcoming applications and games, the Pentium 4 does have a much brighter future than was originally thought. On a performance level, the Athlon can continue to compete with the Pentium 4 but the match up won't be anything like it has been for AMD in the past where the Pentium III was its only competitor. The Pentium 4 platform offers more memory bandwidth and the promise of higher clock speeds than the Athlon's Thunderbird core can deliver.
AMD isn't one to rest on their laurels however and with that in mind they have already scheduled three replacement cores for the Thunderbird. The core being announced today is one of the most highly talked about improvements to the Athlon core ever since the Thunderbird was released in June of last year. This of course is the Palomino core which is found in the latest release of the Athlon processor that AMD is calling the Athlon 4.
Why Athlon 4?
Technically speaking, the Palomino core does mark the fourth AMD Athlon core since the release of the original K7 core in 1999. If we begin counting at the K7 core there was the 0.18-micron Athlon which was based on the K75 core, then the 0.18-micron Thunderbird with on-die L2 cache and the fourth Athlon core would be the 0.18-micron Palomino core.
However our most astute readers will know very well why AMD chose to call the Palomino the Athlon 4. Intel has spent millions of dollars on their Pentium 4 marketing campaign, marking this as their largest processor ramp in history. By the end of 2001 Intel expects the Pentium 4 to completely push out the Pentium III in the markets and in order to do so they must create quite a bit of brand recognition. AMD is obviously using the name Athlon 4 to build off of Intel's aggressive marketing. It is much like what they did with the K6-III processor. Originally the K6-X series of processors used regular numbers after the name to denote the processor series, for example the original K6 was just called the K6 and the second generation part was called the K6-2. Before the third generation K6 launched Intel called their latest processor at the time the Pentium III, so AMD went ahead and called their third generation K6 processor the K6-III.
The reasoning behind calling the Palomino the Athlon 4 is completely marketing. We can go into the reasons why they should've or why they shouldn't have done so but honestly it doesn't matter when it comes down to performance. You all are smart enough not to fall for marketing gimmicks so there's no point in drawing this discussion out any further. AMD decided to call the Palomino the Athlon 4, case closed.
What is the Athlon 4?
You know by now that the Palomino core is what is new about the Athlon 4, but what is exactly different about it? Originally, the Palomino core was supposed to be a minor update to the Thunderbird core that reduced power consumption and heat dissipation by approximately 20%. However that didn't exactly happen on time and instead AMD pushed the release of the Palomino core back a few months. The result of all of this is that the Palomino core actually offers a little more than just a 20% reduction in heat.
For starters, the Athlon 4 is the basis of AMD's four-tiered product line which will be unfolding over the next few weeks and months. The Athlon 4 processor will eventually become the replacement for their current Athlon desktop processor. This replacement won't come until August meaning that, other than the impending 1.4GHz launch, you won't see another "desktop" release from AMD until then. As we predicted back in our CPU Roadmap Update for 2001, the Athlon 4 core will most likely debut in a desktop version at 1.5GHz. The Athlon has already been a huge success in the desktop market and the Athlon 4 will only continue that success and allow it to be more competitive with the Pentium 4 as its counterpart proceeds to aggressively ramp up in clock speed throughout the course of this year.
The second use for the Athlon 4 processor and what it's actually being used in today is in mobile computers. Until now AMD's entire mobile line has actually been pretty disappointing. Their mobile line has been based off of their K6-II+ and K6-III+ processors which have limited AMD's success in the mobile market. While both of these processors were good for their time they can't compete with Intel's mobile Pentium III and mobile Celeron parts, especially when it comes down to allowing for smaller notebooks.
The Athlon 4 being used in the mobile market will change all of that. We already know that the Athlon core is a higher performing desktop part than the Pentium III. And in the mobile market, we expect to see similar results from the Athlon 4 (we'll get into performance a little bit later).
The third function of the Athlon 4 is as AMD's first high-performance workstation processor. Next month AMD will be announcing their 760MP platform, and the Athlon 4 is the first Athlon processor to officially support dual processor operation. The workstation version of the Athlon 4 will be launched alongside this platform.
And the final role of the Athlon 4 will be to kick off AMD's entry into the multiprocessor server market. The MP server market is a very lucrative business for AMD to get into since the profit margins are so high, just look at the profit margins off of Intel's Pentium II Xeon and Pentium III Xeon parts to see the potential for AMD there. However the Athlon 4 will only be a stepping stone for AMD into this market; AMD's 64-bit solutions will truly be the ones to lead the company in this area.
Now that we know the four major roles of the Athlon 4, here's the most important point. The Athlon 4 core that is used in all four of these roles is the exact same core. In fact, the exact same interface is used in the mobile, desktop, workstation and server Athlon 4 processors. This means that the Athlon 4 that is being launched in notebooks today is simply a lower clocked version of the workstation/server Athlon 4 that will be launched in June. And the workstation/server Athlon 4 is nothing more than a lower clocked version of the desktop Athlon 4 that will be launched in August.
Not interested in notebook performance? Well this particular notebook has the same processor that your next desktop might have so pay attention.
The Technology behind Athlon 4
Now you know that the Athlon 4 we're talking about today is the same Athlon 4 you'll see three months from now in your desktop systems, let's talk about what makes it different. AMD put quite a bit of work into the Athlon 4 core using a lot of the knowledge they gained from optimizing the previous Thunderbird core.
Athlon (Thunderbird core)
Athlon 4 (Palomino core)
When designing a microprocessor you don't use the same type of transistors all over the core. The Athlon (Thunderbird) core had 37 million transistors of various types, but it was AMD's first shot at an Athlon core with an on-die L2 cache. The Athlon 4 takes the same Thunderbird core and further optimizes the core by using more optimized transistors for various portions of the core. When you are dealing with the 37.5 million transistors that make up the Athlon 4, such optimizations can result in quite a bit of power savings. According to AMD, these improvements to the Athlon 4 result in a 20% decrease in power use compared to an equivalently clocked Athlon using the Thunderbird core. The die size hasn't changed much either; a small increase from 120 mm^2 to 128 mm^2.
Part of this optimization process included a change in layout of the core which is why the Athlon 4 core does in fact look different than the older Athlon (Thunderbird) core. The change wasn't cosmetic; it was for further performance and power optimizations.
There are four new features that the Athlon 4 offers over its predecessor outside of the power reduction. Three of these features are performance enhancing and the remaining one is a mobile related feature.
Just to set the record straight now, the Athlon 4 does not have an improved Branch Prediction Unit as was originally rumored.
An increase to L1 TLB Entries
The first advantage the Athlon 4 offers is an increase in the number of L1 translation lookaside buffer (TLB) entries. When a processor accesses main memory it doesn't directly reference the physical addresses in memory. Instead there is a set of virtual addresses that map onto these physical addresses in memory. The process of translating virtual addresses to physical addresses is necessary for actually getting to data in main memory. Unfortunately, your CPU doesn't like to have to go to main memory. The reason being that when your CPU must go to main memory it has to travel down the FSB, through the North Bridge and down the memory bus before it can actually get to the main memory. A way of avoiding this long trip is by caching.
You all are aware of two particular types of processor caches, the L1 and L2 caches. These caches can store frequently used data. Well, there is also another type of a cache known as the Translation Lookaside Buffer or TLB for short. The TLB caches the translated addresses that result from this virtual address to physical address translation process. The probability of a CPU finding the address it needs in its TLB is extremely high, usually on the order of 99%; this is known as the processor's TLB hit-rate. This is quite good since in the event that the CPU cannot find an address it needs in the TLB, the penalty can be incredible and the CPU's performance suffers in turn. In order to resolve a single address the penalty can be 3 clock cycles. Multiply that by the number of addresses that must be looked up in main memory and you can see where the CPU would end up slowing down considerably because of this. Upon a hit to the TLB this lookup can be done in 1 clock cycle, improving performance by 200%.
The TLB for the L1 cache on the Athlon 4 has received an increase in the number of entries, which increases the hit rate for the Athlon's TLB. The Thunderbird only had a 24-entry L1 TLB compared to the 32-entry L1 TLB on the Pentium III for the instruction cache and a 32-entry TLB for the L1 data cache as opposed to the Pentium III's 72-entry L1 D-cache TLB; Unfortunately AMD did not have the exact number of L1 TLB entries of the Athlon 4. We simply know that they did increase the number.
This increase actually only amounts to a marginal real-world performance increase for the Athlon 4 over the Athlon (Thunderbird) so you shouldn't get too excited over it.
Data Prefetch
The Athlon 4's L1 and L2 cache sizes and mapping remain unchanged. As a refresher, the Athlon 4 has a 2-way set associative 64KB L1 instruction cache and a similarly associative 64KB L1 data cache. The Athlon's L2 cache is a 16-way set associative exclusive 256KB L2 cache. The fact that it is an exclusive architecture means that the L1 addresses are not duplicated in the L2 cache allowing AMD to claim a total on-die cache of 384KB for the Athlon 4. That part of the equation remains unchanged, what did change was that the Athlon 4 now has an automatic data prefetch mechanism that works alongside its cache.
This is similar to the Pentium 4's hardware prefetch which predicts what data it will need before it is requested and fetches it from main memory into its cache. This process obviously increases FSB and memory bandwidth usage and it does tend to show more of a performance improvement on higher clocked/higher bandwidth FSB/memory platforms. This does translate into DDR SDRAM being much more useful for the Athlon 4 than it was on the Athlon (Thunderbird).
The data prefetch that is now a part of the Athlon 4's core has actually been around for quite a while with desktop microprocessors. The Athlon 4's data prefetch is simply an evolution of previous prefetch designs. The data prefetch functions can also be software initiated which will take precedence over the Athlon 4's own data prefetch mechanism.
This is where the bulk of the Athlon 4's performance increase does come from and while it isn't an incredible boost in performance, it is respectable nonetheless.
The Athlon 4 gets SSE
If you'll remember back to the release of the original Athlon microprocessor, it received a total of 19 new instructions that AMD dubbed Enhanced 3DNow! These were all Single Instruction Multiple Data (SIMD) instructions and they actually turned out to be a partial SSE implementation. The Athlon 4 takes this one step further and adds 52 new instructions for what AMD calls 3DNow! Professional which is really the same SSE instructions that the Pentium III debuted with over two years ago.
While the SSE optimizations won't buy the Athlon 4 an incredible amount of performance in most real world situations, they will ensure for more equal treatment under certain applications that were arguably more SSE optimized than they were 3DNow! optimized.
For those of you that aren't familiar with SIMD instructions, they allow a single instruction to be applied to multiple datasets. This comes in handy with many 3D operations such as the transformation of coordinates from mathematical space to 3D vector space. These transformations require quite a bit of repetitive math, including multiple addition, subtraction, multiplication and division functions. By applying SIMD principles to this transformation a single add command can be applied to multiple data points simultaneously saving quite a bit of time.
AMD's x86-64 line of processors will actually receive a full set of SSE2 instructions, but for now the Athlon 4 is only compatible with the original SSE instructions. Don't expect performance to improve too much because of this, but maybe it will quiet those that always accuse benchmarks of being "SSE optimized."
Lower voltage, PowerNow! and finally, a Thermal Diode
Since the Athlon 4 is initially being launched as a mobile solution it does boast a few mobile optimized features. For starters, at 1GHz the Athlon 4 runs at 1.4V as opposed to 1.75v for the 1GHz Athlon (Thunderbird). This lower voltage operation is made possible by the transistor and layout optimizations we talked about earlier in this article.
The Athlon 4 does feature AMD's PowerNow! technology. For a quick refresher, AMD's PowerNow! allows the processor to dynamically change its clock speed and operating voltage depending on the application demands on the CPU. For example, a 1GHz mobile Athlon 4 doesn't need to run at 1GHz/1.4V if you are simply running MS Word. In this case it may throttle down to 500MHz/1.2V and automatically move up to 750MHz if you start to play a DVD (For more information on PowerNow! read our overview of the technology here).
The Athlon 4's PowerNow! implementation is relatively unchanged from the K6-II+ and K6-III+ processors. The only difference being that with both of those processors, in order to get respectable performance the processors would have to spend more time in the higher performance modes while the Athlon 4 can perform relatively well in its lower power modes. The Athlon 4's PowerNow! implementation allows for a total of 32 speed/voltage steps between 500MHz @ 1.2V and the maximum clock speed of the processor. Realistically speaking however you will probably only see between 4 and 8 steps used in actual implementations of the technology.
PowerNow! isn't too useful in desktop machines but mobile implementations of the processor will definitely benefit. In order for the technology to be taken advantage of there must be BIOS and chipset support.
The last feature of the Athlon 4 is an on-die thermal diode which measures the internal core temperature, much like what the Pentium III and Pentium 4 have. This is a very important feature because now the processor can not only tell what its internal core temperature is but, if implemented properly, the processor could throttle down or even shutoff if its temperature got too high.
There has been criticism for the Pentium 4 supporting this feature yet it is extremely useful. It would avoid the burnouts that have occurred in the past where users have either installed poor heatsinks, have failing fans or didn't even connect their fans. We have yet to confirm if the Athlon 4 has this sort of thermal protection enabled or not, but at this point there is nothing stopping AMD from doing so.
The on-die thermal diode requires the motherboard to be designed with it in mind. The thermal diode must be hooked up to a hardware monitoring chip, such as that integrated in VIA's 686 series South Bridges as well as BIOS support.
Mobile Athlon 4 Notebooks & Chipsets
Since the processor being launched today is the mobile Athlon 4 we should probably talk about the notebooks that are going to be using the chip. Initially the Athlon 4 will be available in four speed grades: 850MHz, 900MHz, 950MHz and 1GHz all at 1.4V. These are all 200MHz FSB (100MHz DDR) parts. For power consumption and layout reasons there won't be any 266MHz FSB mobile Athlon 4s anytime soon.
Compaq has already announced and will be shipping notebooks based on the mobile Athlon 4 processor. These should already be in stores by publication. While no other manufacturers have announced yet we can expect notebooks from HP and probably Sony as well.
Currently there are only two chipsets that will be used with the mobile Athlon 4: the ALi MAGiK1 and the VIA KT133A. The MAGiK1, in spite of its DDR SDRAM support, is actually our least favorite of the two. As we noticed in our latest Socket-A Chipset Roundup, the MAGiK1 when coupled with the 200MHz FSB performed quite poorly. With DDR SDRAM it was even slower than the VIA KT133A with PC133 SDRAM. Interestingly enough, AMD chose the MAGiK1 to run their official battery life tests on instead of the KT133A (which they chose to run their official performance numbers on, can you guess why?). This leads us to believe that the MAGiK1 may consume less power than the KT133A. Other than the chipset difference both their performance and their battery life tests were conducted on identical systems.
The MAGiK1 will offer PC100/133 SDRAM and DDR SDRAM support while the KT133A will only offer PC100/133 SDRAM support since it has no DDR memory controller. Both of these chips are relatively large, and consume quite a bit of space on an extremely cramped mobile PCB.
The mobile Athlon 4 processor is packaged exactly the same as its upcoming workstation counterpart, meaning it is the same size as a current generation Athlon (Thunderbird). This combined with the fact that motherboard manufacturers have to make room for the chipset is going to unfortunately keep the Athlon 4 out of the thin and light notebooks initially.
This means that the only notebooks you're going to be able to find with the Athlon 4 at the start are desktop replacement units. There is definitely a market for these types of notebooks as they do garner over 40% of the market share, however thin and light notebooks are increasing in popularity and AMD will have to eventually roll out a different packaging in order to meet the needs of this market. AMD will most likely explore a BGA or micro PGA interface for future versions of the mobile Athlon 4.
Most of the Athlon 4 notebooks will have battery lives in the 3 - 3.5 hour range according to AMD using Ziff Davis Battery Mark as an indicator of battery life.
Athlon 4 Performance
Although we really wanted to give you all the performance of the workstation Athlon 4 here we couldn't since AMD is only announcing the mobile Athlon 4 today (even though they are the exact same CPU). Luckily, since they are the same CPU, the benchmarks AMD is releasing today are exactly what you can expect from the desktop and workstation versions of the Athlon 4 (except those won't appear at 1GHz and lower clock speeds).
We will save our benchmarks on the Athlon 4 until the official workstation processor release but if you're interested, AMD is providing benchmarks on the processor that indicate a 2 - 15% increase in performance over an identically clocked Thunderbird. Some interesting numbers to quote from AMD include a 6% advantage under Quake III Arena, a 5% increase under Business Winstone 2001 and a 10% advantage under SYSMark 2000. The majority of this performance increase does come from the data prefetch of the Athlon 4.
Mobile Athlon 4 (PGA) vs Mobile Pentium III (BGA)
In terms of notebook performance, the mobile Athlon 4 should offer a considerable performance advantage over the mobile Pentium III. However the one advantage that the mobile Pentium III still does have is that it is available in a much smaller packaging and is thus able to be in much smaller form factor notebooks.
Mobile Athlon 4 vs Mobile Pentium III Module (Chipset + CPU)
Mobile Duron is here too
Along with the launch of the mobile Athlon 4 is the mobile Duron. The mobile Duron is based on the Morgan core which will actually be present in desktop Durons later this year. The Morgan core is identical to the Palomino core of the Athlon 4 except it does have the smaller L2 cache (64KB) that the Duron has always had.
The mobile Athlon 4 will be found in notebooks priced at $1,800 and above while the mobile Duron will be found in high performance value notebooks priced under $1,800. You should be ware of the fact that there are some notebooks out there based on the desktop Duron processor using the Spitfire core. If you're in the market for a notebook with a Duron make certain that it uses the mobile Duron and not the regular desktop Duron.
An updated roadmap
AMD has yet again updated their processor roadmap and they will continue to do so as we get closer and closer to 2002.
As we've mentioned before, the workstation Athlon 4 (Palomino core) will be released next month. The workstation version of the Athlon 4 will debut at a much lower clock than 1.5GHz but still higher than the 1GHz clock of the mobile Athlon 4. This will allow AMD to follow in Intel's footsteps of working out all the kinks in manufacturing the Athlon 4 with the mobile and workstation parts that ship in relatively low volumes compared to the desktop parts. This should prove to make the eventual desktop launch a very smooth one.
AMD does have quite a bit of time to get everything worked out with the Athlon 4 core and increase yields since the desktop version of the Athlon 4 won't hit the streets until the third quarter of this year. This launch will most likely in August, and it will make its introduction at 1.5GHz according to our CPUs in 2001 Roadmap Update. This makes the upcoming 1.4GHz Athlon the last Thunderbird based solution we'll see from AMD.
Since there won't be any workstation version of the Morgan based Duron, we won't see a desktop Duron with the Athlon 4 enhancements until after the desktop Athlon 4 launch. This puts the Duron (Morgan) desktop launch at late August or September of this year. Remembering that the intended market segment for the Duron is the value segment where integrated video is a must, the Morgan core may not provide as great of a performance increase as the Palomino offers for the Athlon 4. The reason being that data prefetch is dependent on having a high bandwidth FSB and memory bus, yet most Duron platforms won't have the same PC2100 DDR SDRAM that their Athlon counterparts will.
ALi, SiS and VIA are working to change that as their roadmaps do show value DDR platforms becoming available in the second half of this year. If they abide by their roadmaps then the Morgan core should truly take the value market segment to some very high performance levels. And it will need to because the next incarnation of the Celeron is rumored to be much like a Pentium III; the Duron won't have as easy of a time competing as it once did.
In the first half of 2002 AMD is going to be releasing the successor to the Palomino core with their Thoroughbred. The Thoroughbred will be a 0.13-micron solution, making it even cheaper to produce and will be available in both desktop and mobile versions. If AMD's internal plans are anything like those of Intel's then the Thoroughbred may end up with a 512KB L2 cache, but we have yet to receive confirmation on that. The reason we have to hypothesize this is because a 0.13-micron Athlon 4 will take up 52% of the die of the current 0.18-micron parts. With all of that saved space AMD is bound to use some of it to improve performance.
The Thoroughbred will also see a mobile launch with PowerNow! support around the same time but what is truly interesting is that there will be no Thoroughbred part for the workstation/server markets. Unless AMD specifically disables SMP on the Thoroughbred CPUs (which they haven't done thus far, the Thunderbird does work in SMP mode although not officially sanctioned by AMD), it would make much more sense to run a pair of Thoroughbred cores on 760MP than it would to run a pair of Palomino based Athlon 4s. If AMD is serious enough about keeping users from doing this, they could very well disable SMP on the Thoroughbred CPUs. We have no reason to believe AMD would do this, but then again they've never been in a position like this before. It'll be interesting to keep an eye on.
Later in the first half of 2002 AMD will be releasing the Duron version of the Thoroughbred core known as Appaloosa. The only difference between Appaloosa and Thoroughbred will be cache and maybe FSB frequency. Appaloosa will also be made into a mobile part around the same time.
Judge Barton presiding?
It's funny how rumors get started. The latest one happened to be the source of the name for AMD's next Athlon core after Thoroughbred. The Barton core will be the second 0.13-micron Athlon core and it will be hitting the streets in the second half of 2002, well over a year from now so it is too early to announce specs as they may change. The name Barton comes from the first Triple Crown winner (a horse race), a horse named Sir Barton. If you consider that the rest of the codenames on AMD's Athlon roadmap are from horses then this makes sense. That isn't to say that there aren't other internal meanings for the name among the folks at AMD.
In terms of the actual name of the processor based on the Barton core, it will most likely continue to be Athlon. AMD hasn't spent all this time creating the Athlon brand just to throw it away in a year. But enough talk about names, what's the real deal behind Barton?
Silicon on Insulator
Anyone that is even somewhat familiar with CPUs will know that they are made up of millions of transistors. In the case of the Athlon 4, there are 37.5 million transistors to be specific. But what is a transistor?
As we've explained before, a transistor is much like an electrical switch with two positions on and off. The type of transistors used in CPUs like the Athlon 4 and the Pentium 4 are what are known as Complementary Metal Oxide Semiconductors or CMOS transistors.
Today's CMOS transistors are made up of a few key parts: doped Silicon (or any other semi-conductor), metal and an oxide separating the metal from the Silicon. Silicon by itself isn't a conductor, but by introducing chemical "impurities" into the Silicon through a process known as "doping" the Silicon can conduct under certain circumstances (thus the name semi-conductor is given to it). The way a transistor conducts electricity is by applying a voltage to the metal gate that is present in the transistor. If a low voltage is present then the gate closes and current can flow through the transistor. If a high voltage is present then the gate opens and no current can flow.
Note: Thanks to AnandTech reader Todd Fuller for pointing out that modern day capacitors use a polysilicon for the gate.
This switching takes place very rapidly, and the faster our processors get the greater the need for faster and cooler running transistors becomes. One way of accomplishing this is by making smaller transistors which is what happens when processors undergo a "die shrink" (e.g. from 0.18-micron down to 0.13-micron). Unfortunately this is quite expensive and as they do get smaller their performance begins to become limited by the wiring present in the chip itself. This is where a switch from Aluminum to Copper wiring helps out, which AMD has already done with their higher clocked Thunderbirds and all Athlon 4 processors.
Another way to improve the speed of transistors is to implement a faster type of switch. Before a transistor can conduct electricity it must charge itself up and then release the charge when the transistor is switched "off." This process actually takes up quite a bit of time. Those that are familiar with this charging and release of charge will know that we are referring to the charging and discharging of a capacitor, or in this case the internal capacitance of the transistor.
If the time constant for charging and discharging the transistor can be decreased, the overall performance of the transistor can increase. This is where Silicon on Insulator (SOI) comes into play.
Silicon on Insulator reduces the internal capacitance of the transistor by sandwiching an oxide between the processor's Silicon substrate and an extremely thin layer of Silicon. This vastly reduces the amount of charge being stored between the doped Silicon and the processor's Silicon substrate which in turn allows the transistors to switch faster thus allowing higher clock speeds. SOI will also decrease the power usage of these transistors since less current is wasted charging up the capacitance of the transistors.
This technology will be first introduced by AMD with their Barton core although IBM has already demonstrated such technology in their processors.
Hammer and Final Words
As you can also tell by their updated roadmap, AMD has pushed their x86-64 processors, SledgeHammer and ClawHammer back until the second half of 2002. Very little is known about these two but they are aimed at the same markets as Intel's forthcoming Itanium processor.
Now that the Athlon 4 is here, the big question everyone is asking is "will it work with current Socket-A motherboards?" AMD actually told us that as long as motherboard manufacturers adhere to the guidelines they set forth, a motherboard purchased today would work with not only the Athlon 4 but also the Thoroughbred and Barton cores. This means that the Thoroughbred and Barton cores will both be on Socket-A Athlons as well.
Don't get too excited though. Unfortunately not all motherboard manufacturers to adhere to AMD's guidelines properly. Voltage and BIOS support is necessary for your motherboard to work with the Athlon 4 as well as the upcoming Thoroughbred and Barton cores. And even if your current motherboard does work with the future cores, you may not want to even use it since newer motherboards will have more features, newer chipsets, greater performance etc… But it is nice to know that AMD is sticking with Socket-A for the Athlon family.
Now that the mobile Athlon 4 is here, it is time to start the countdown for the workstation version. Although the workstation Athlon 4 will be faster clock for clock than a desktop Thunderbird based Athlon, you will be able to get a much higher clocked Athlon (Thunderbird) than you will a workstation Athlon 4 which will end up outperforming the new core. The forthcoming desktop version of the Athlon 4 will combine its features and a higher clock speed making that ideal for your single processor systems.
But that desktop launch is still at least four months away. In the mean time, AMD has one more ace up their sleeve…or should I say two more.