AMD dual socket six-core LV server

WHILE INTEL HAS the overall performance lead across desktops, workstations and servers alike, AMD had to focus on adding more cores to its dies to make up for the speed shortfall, at least before the long awaited Bulldozer cores appear, maybe in about a year's time.

There are still many types of jobs where the number of cores can be more important than the individual core speed, though. For instance, highly multithreaded tasks or situations where many small tasks that are more I/O than CPU bound - like networking or database search - proceed in parallel. In such cases, the lowest possible CPU power consumption coupled with the availability of many cores to take care of the each thread or task with minimal thread switching overhead can be very helpful.

AMD now has its ultra low power 40W "Istanbul" - or Opteron 2419EE to be precise - six-core CPUs for exactly such applications. While its quad-core "Shanghai" Opterons reached a maximum frequency of 2.3GHz, the six-core part had to give up some clock speed, down to 1.8GHz, to manage the thermal load for six cores. However, the Istanbul chip keeps the Opteron line's full 1GHz Hyper Transport 2 speed as well as dual-channel DDR2-800 memory per CPU.

We had a look at one of the first test platforms using these chips, the reference Gigabyte server mainboard platform with two 1.8GHz LV Istanbul Opteron 2419EE processors, providing a total of 12 cores. And, to spice things up, we also ran some of the well multithreaded desktop benchmarks to check how far this configuration will go with the codes our readers are more familiar with.

The feature rich GA3-C board from Gigabyte, based on the Nvidia Nforce Professional 3600 MCP system chipset, was set up with 4GB of DDR2-800 registered ECC server memory, one for each of the four channels, as well as a Sapphire ATI HD4870 2GB graphics card fitting the only available PCI-e slot. The usual dual Gigabit Ethernet, SATA plus SAS storage interfaces, as well as Gigabyte's integrated server management circuitry complete the feature set.

We used the plainest possible default aluminum-only heat sinks with small 6cm fans and no heat pipes or such widgets at all. With this in place we installed Windows 7 64-bit and a bunch of benchmarks.

First off was 3Dmark 06 which came up with a pretty decent CPU score for a 1.8GHz CPU.

What's more important is that the nearly four year old benchmark scaled well across eight cores, leaving the other four cores for other system needs. The new 3Dmark Vantage would scale well across up to 32 threads.

Now, look at the Sandra 2009 CPU and memory results below. The Sandra 2009 benchmark test uses all the threads available.

By the way, the heat sinks were barely hot during these benchark runs, a testimony to the low actual power usage and heat generation of the new low power Istanbul CPUs. Keep in mind that many new games and other desktop software can also make use of many threads at once - with a combination of physics, AI, effects and background tasks - to fill the new cores with work.

Overall, We're quite happy with the performance of the low power technology in general benchmarks, and will also take a look at the server-specific point of view in future tests. While the CPU clock rates are down, memory and I/O bandwidth wasn't reduced, allowing fairly balanced performance to be achieved across most applications.

Also in the future tests, we'll look more closely at the actual power usage graph of AMD's low power Istanbul chip and how it compares against the low power versions of both the old Intel Harpertown Xeon, the L5430 CPU, as well as the new L5500 series low voltage Nehalem Xeons. µ