The Opteron 6276: a closer look

Making Sense of the New Interlagos Opteron

This second look at the current Xeon and Opteron platforms added OLAP, ERP, and OLTP power and performance data. Combine this with our first review and the other publicly available benchmark and power data and we should be able to evaluate the new Opteron 6200 more accurately. So in which situations does the Opteron 6200 make sense? We'll start with the perspective of the server buyer.

Positioning the Opteron 6276

First let's look at the pricing. The Opteron 6276 is priced similar to an E5649, which is clocked 5% lower than the X5650 we tested. If you calculate the price of a Dell R710 with the Xeon E5649 and compare it with a Dell R715 with the Opteron 6276 with similar specs, you end up more or less the same acquisition cost. However, the E5649 is an 80W TDP and should thus consume a bit less power. That is why we argued that the Opteron 6276 should at least offer a price/performance bonus and perform like an X5650. The X5650 is roughly $220 more expensive, so you end up with the dual socket Xeon system costing about $440 more. On a fully speced server, that is about a 10% price difference.

The Opteron 6276 offered similar performance to the Xeon in our MySQL OLTP benchmarks. If we take into account the hard to quantify TPC-C benchmarks, the Opteron 6276 offers equal to slightly better OLTP performance. So for midrange OLTP systems, the Opteron 6276 makes sense if the higher core count does not increase your software license. The same is true for low end ERP systems.

When we look at the higher end OLTP and the non low end ERP market, the cost of buying server hardware is lost in the noise. The Westmere-EX with its higher thread count and performance will be the top choice in that case: higher thread count, better RAS, and a higher number of DIMM slots.

AMD also lost the low end OLAP market: the Xeon offers a (far) superior performance/watt ratio on mySQL. In the midrange and high end OLAP market, the software costs of for example SQL Server increase the importance of performance and performance/watt and make server hardware costs a minor issue. Especially the "performance first" OLAP market will be dominated by the Xeon, which can offer up to 3.06GHz SKUs without increasing the TDP.

The strong HPC performance and the low price continue to make the Opteron a very attractive platform for HPC applications. While we haven't tested this ourself, even Intel admits that they are "challenged in that area".

The Xeon E5, aka Sandy Bridge EP

There is little doubt that the Xeon E5 will be a serious threat for the new Opteron. The Xeon E5 offers for example twice the peak AVX throughput. Add to this the fact that the Xeon will get a quad channel DDR3-1600 memory interface and you know that the Opteron's leadership in HPC applications is going to be challenged. Luckily for AMD, the 8-core top models of the Xeon E5 will not be cheap according to leaked price tables. Much will depend on how the 6-core midrange models fare against the Opteron.

The Hardware Enthusiast Point of View

The disappointing results in the non-server applications is easy to explain as the architecture is clearly more targeted at server workloads. However, the server workloads show a very blurry picture as well. Looking at the server performance results of the new Opteron is nothing less than very confusing. It can be very capable in some applications (OLTP, ERP, HPC) but disappointing in others (OLAP, Rendering). The same is true for the performance/watt results. And of course, if you name a new architecture Bulldozer and you target it at the server space, you expect something better than "similar to a midrange Xeon".

It is clear to us that quite a few things are suboptimal in the first implementation of this new AMD architecture. For example, the second integer cluster (CMT) is doing an excellent job. If you make sure the front end is working at full speed, we measured a solid 70 to 90% increase in performance enabling CMT (we will give more detail in our next article). CMT works superbly and always gives better results than SMT... until you end up with heavy locking contention issues. That indicates that something goes wrong in the front end. The software applications that do not scale well could be served well with low core count "Valencia" Opteron 4200s, but when we write this, the best AMD could offer was a 3.3GHz 6-core. The architecture is clearly capable of reaching very high clockspeeds, but we saw very little performance increase from Turbo Core.

What we end up with then is more questions. That means it's time for us to do some deep profiling and see if we can get some more answers. Until then, we hope you've enjoyed our second round of Interlagos benchmarking, and as always, comments and feedback on our testing methods are welcome.