AMD's 3rd generation Opteron versus Intel's 45nm Xeon: a closer look

Conclusion

When it comes to floating-point performance, we feel we can say we have a very good picture of what AMD's and Intel's best are capable off. The Barcelona floating-point architecture is able to beat the 53xx in quite a few benchmarks, but the Xeon 5472 shows that AMD's third generation Opteron is late to the party. Our FLOPS, LINPACK, and rendering benchmarks show that the Xeon 5472 is at least as good as or better than AMD's latest in raw FP performance on a clock-for-clock basis.

We have less data on "pure" integer performance, with the exception of our Fritz Chess benchmark. This benchmark gave us a first hint that the improvement in integer performance from the Opteron 22xx to the Opteron 23xx is probably rather small. The single-threaded SpecInt2006 numbers published by IBM are probably not optimal, but also confirm this:

• A 1.9GHz Opteron 2347 got a score of 11.3, 9.97 base
  
• A 2GHz Opteron 2212 gets a score of 10.8, 9.77 base
  
• A 2GHz Xeon E5335 gets a score of 15.5, 14 base

This indicates that the Opteron 23xx is about 10% faster in integer tasks than the 22xx series. Considering that the best SPECint_rate2006 score of AMD's quad-core at 2.5GHz is 102 while Intel's 5460 (3.16GHz) is already at 138, we think it is safe to assume that the integer performance of AMD's Barcelona is still not up to Intel Core levels. The Xeon 5365 at 3GHz is also able to deliver a significantly higher score (117). This, together with our own benchmark data, makes us believe that the Xeon 54xx based on the Penryn architecture will beat the best AMD chips on every aspect of raw processing performance: integer, legacy x87 FP, and SIMD (SSE). It is clear now why Intel's CPUs are so dominant in desktop and workstation workloads.

Add to this a significant clock advantage: there is already a 3.2GHz Xeon 5485 (150W). If you prefer a less power hungry CPU, Intel can provide a 3GHz 5472 that is still clocked 20% higher than what AMD will be able to deliver 2 to 3 months later. Although the 3GHz models are quite pricey (>$1000), you can already find a 2.5GHz quad-core Xeon for $316. That's the same price as a 1.9GHz Opteron 2347 chip. There is little doubt in our mind that a 2.5GHz Xeon is faster in almost every application we can think off, so Intel's newest Xeon does have the price/performance crown as well.

While AMD loses quite a few battles, the war is far from lost. The server/HPC situation is entirely different from the desktop scene where the Core 2 Quad overpowers the Phenom in almost every benchmark. There is more to server and HPC performance than simple raw processing power. Intel's flagship still has an Achilles heel: the platform it is running on has higher latency and much lower bandwidth than AMD's platform. Once you really stress all those cores with many threads, AMD's platform starts to pay off.

Look at the summary of our benchmarking below. (Blue numbers mean Intel is faster; green show a victory for the AMD chip).

* Faster LINPACK binaries from Intel were available at the time that we finished this article.

To put it in car terms, our SPECjbb, LINPACK, and MySQL benchmarks have shown that Intel's "powerful CPU engines" sometimes have problems putting the "massive torque" to the "wheels". You may feel for example that using four instances in our SPECjbb test favors AMD too much, but there is no denying that using more virtual machines on fewer physical servers is what is happening in the real world. Intel's best have a solid lead over AMD's quad-core in rendering benchmarks, but some HPC, Java and MySQL benchmarks show that the 2.5GHz Barcelona is able to keep up with (or come close to) a 3GHz Xeon 5472. That is impressive, on the condition that we finally see some higher clocked Opteron 23xx chips in commercially available servers.

We still cannot draw any solid conclusion on the server performance of AMD's quad-core as no MS Exchange, SAP ERP, TPC-C, or TPC-H results have been published. In fact, with the exception of the SPECjbb and MySQL numbers in this article, all server benchmarks on AMD's third generation Opteron are MIA. This situation will probably continue for a few more months as most of these benchmark results traditionally come from OEMs and not AMD.