AMD has officially launched its Opteron 6100 series processors, code-named “Magny-Cours.” Available in 8-core and 12-core flavors, the new 6100 parts are targeted for 2P and 4P server duty and are being pitched against Intel’s latest high-end Xeon silicon: the 6-core Westmere EP processor for 2P servers and the upcoming 8-core Nehalem EX processor for 4P-and-above servers.

With the 6100 launch, AMD’s battle with Intel for the high-end x86 server market enters a new era. In the two-socket server space, Intel’s Westmere EP retains the speed title, clock-frequency-wise. At the same time, Nehalem EX, due to be announced tomorrow, will give Intel exclusive ownership of the 8P-and-above x86 server market. Meanwhile, AMD will use Magny-Cours to try to outmaneuver Intel with better price-performance and performance-per-watt on two-socket and four-socket machines. According to John Fruehe, director of product marketing of the server and workstation division, their whole focus is about value. “We’re going to be able to deliver more cores and more memory for less money,” he says. Pricing on the new CPUs range from a low of $266 up to $1,386 at the top end.

While Intel can still deliver faster cores on its Westmere EP, thanks in part to its 32nm process technology, AMD, with its 45nm technology, has opted to go for more cores that run proportionally slower. “Their per-core performance is higher than mine,” admits Fruehe. “But their per-core price is much higher than mine and their per-core power [draw] is much higher than mine.” The fastest Westmere EP CPUs top out at 3.33 GHz for the 6-core version and 3.46 GHz for the 4-core version. In contrast, the speediest 12-core and 8-core Magny-Cours come in at 2.3 GHz and 2.4 GHz respectively.

But performance-wise, the new Opterons still make a good showing against their higher-clocked and more expensive Xeon rivals. Matched against a 3.3 GHz 6-core Westmere EP (Xeon X5680), AMD says its 2.2 GHz 12-core Magny-Cours (Opteron 6174) essentially breaks even on the SPECint_rate2006 metric for integer performance and is about 20 percent faster as measured by SPECfp_rate2006 for floating point. That comparison seems especially favorable for AMD, considering the top-bin X5680 runs about $500 more than AMD’s middle-of-the-road 6174. Better yet, the Xeon part is rated at 130 watts TDP, while the Opteron comes in at 80 watts ACP — although these power ratings are not directly comparable.

AnandTech ran its own tests that pitted a 12-core Magny-Cours against a 6-core Westmere EP. For HPC workloads in particular, the Opteron performed very well, besting its Xeon competition in an LS-DYNA crash simulation code and a Fluent fluid dynamics test. The benchmarkers attributed the better HPC performance in these cases to the additional memory channel — 4 for the Magny-Cours versus 3 for the Westmere EP — and the additional cores.

In the 4P arena, the performance matchup with Nehalem EX is less certain. Here Intel brings the core count up to 8 and matches Magny-Cours with 4 memory channels per socket. Nehalem EX will also support up to 16 DIMMs per socket versus 12 for Magny-Cours. Cache-wise, Intel’s 8-core chip sports a full 24 MB of L3 cache, against 12 MB for AMD’s top offering. But Fruehe says Nehalem EX only supports up to 1066 MHz memory when the DIMMs are packed, while the Opterons can support all 12 DIMMs with 1333 MHz RAM. In addition, the EX has an extra buffer on each channel, which adds latency to the memory access.

Nevertheless, AMD intends to push the 6100 heavily for 4P platforms. According to Fruehe, the 6100 design eliminates the so-called “4P tax” that has made 2-socket machines the sweet spot in the server market for years. “If you think about your typical HPC cluster today, everybody buys 2P boxes because they’re cheap and easy to cluster together,” explains Fruehe. “You could get greater performance for a lot of workloads by jumping to a 4P — as long as you’re not saturating your interconnect — and end up saving a lot of money.”

Since Magny-Cours and the G34 chipset support both 2P and 4P designs, the processor and memory cost increase only linearly as you double up the CPUs. The savings come in because your motherboard, chassis, and power supply costs go down relative to two 2P boxes. And since you’re cutting the number of server nodes in half, you also save on interconnect adapters and switches, which is a significant chunk of the overall cost of a system. Also, with half as many nodes, your cluster is easier to manage, and in some cases, will require less costly software licensing.

The $266 to $1,386 price spread for Magny-Cours will look especially attractive for large-scale 4P setups compared to the more expensive Nehalem EX. (As of Monday, prices on the EX series have not been announced, but are expected to range between $800 to $3,600.) For HPC deployments in particular, where hundreds or thousands of nodes are involved, the up-front cost savings are likely to be significant.

On the other hand, AMD has decided not to play at all in the 8P server market. In doing so, the company will cede the x86 portion of this market entirely to Intel and Nehalem EX. The rationale is that the market volume is too small for AMD. Fruehe estimates that today the 8P space accounts for only 1600 to 1800 servers per quarter worldwide (less than 60,000 CPUs per year), and believes those numbers are shrinking. AMD has calculated that the price premium and system complexity associated with an 8P system won’t be worth it for the vast majority of customers. And as core counts plus memory capacity grow, many of these 8P SMP applications may be able to transition down to 4-socket servers. “Ultimately, the value we’ll be able to deliver in a 48-core 4P and the type of price points we can hit will make it increasingly difficult for people to justify spending the money on a Nehalem EX platform,” says Fruehe.

So far, most of the major system manufacturers have signed up for the Opteron upgrade, including HP, Dell, Cray, SGI, Appro, Penguin Computing, Supermicro, Colfax, Atipa and others. Interestingly, IBM is missing from this list, but they may be waiting for a more opportune moment to jump on the 6100 bandwagon. A new OEM partner for Opteron is Acer, which will be introducing 6100-based servers, including HPC boxes, in Europe and Asia, and later this year in North America.

If the server makers come through, AMD’s strategic focus on 2P and 4P servers may pay off. In the highly price-performance sensitive HPC market, the 6100 products could help the company recapture some of the market share it has lost over the last couple of years. And despite the momentum Intel has built for its Xeon products, customer loyalty for CPUs is only as enduring as the next procurement cycle.