As with the desktop side of things, 2005 had been a rough year for Intel even on the workstation and server front as the AMD Opteron repeatedly advanced through to displace Intel's best offerings in both performance and efficiency (comprising of thermal and power considerations). After all, AMD's Opteron is based on the tried and tested Athlon 64 and Athlon 64 X2 CPU architecture that we are all familiar with and past rankings have pegged them always one rung better than Intel's options. Likewise for the Xeon, they were mostly variants from the desktop side based on the NetBurst architecture that didn't really shine. In fact, the only dual-core Xeon model that Intel peddled for quite a while for 2-way SMP systems was a 2.8GHz Paxville DP that was based upon the ill-famed Smithfield core.
Just like in the mobile and desktop space, Intel's savior in this highly contested and prestigious workstation/server segment was none other than the Core microarchitecture which as we've explained in our IDF articles, are tuned differently to be deployed in all three sectors. Launched in June this year (ahead of the Core 2 series for the desktop), the Xeon 5100 series returned with a vengeance and almost immediately rivaled and even surpassed AMD at times as far as dual-processor configurations (2-way SMP) are concerned in performance, power consumption, thermal output and even price. It was a well-needed equalizer for Intel to get back in the game and prevent further market share erosion in this high-performance computing space. Here's how the Xeon 5100 series stacks up currently:-\
|Processor Model / Processor Characteristics||Clock Speed||L2 Cache||Front Side Bus (MHz)||Max TDP (W)||Intel VT||Intel EM64T||Demand-Based Switching (DBS)||Estimated Price (US$)|
|Xeon 5148 LV||2.33GHz||4MB||1333||40||Yes||Yes||Yes||N.A.|
Take note that the Xeon processor 5100 series (Woodcrest core) shown here greatly differs from the similarly numbered 5000 series (Dempsey core). Woodcrest is basically what Conroe is to the desktop segment but with SMP capability and a 1333MHz PSB, while Dempsey is similar to the Presler core (used in the Pentium D today) with SMP capability and a 1066MHz PSB. Given the massive comparisons we've shown you between the Core microarchitecture used in Core 2 processors versus the Netburst microarchitecture in the Pentium D processors, the difference between them is as clear as day and night. Thus you can see why the Xeon 5100 is a crucial pawn in Intel's lineup to move forward.
From the Xeon processor 5100 series stack, you can see that there's a wide variety of processor configurations available to meet funding quota and/or performance needs. These processors are best designed to be used in dual processor (DP) platforms right from the start to give you give multi-threading support of two threads per socket or up to four when both processor sockets are populated on the DP platform. There's even one SKU that's ideal for high-density computing needs via the low voltage 40W TDP part. All have Virtualization Technology, true 64-bit processing, 64-bit memory addressing capability among other well-known features such as supporting Execute Disable Bit and more. Demand-Based Switching (DBS) however, isn't available on all processors. For those who aren't too familiar with this feature, it's based upon Intel's SpeedStep technology that stemmed from mobile processors for throttling down processor frequencies when idle or at low loads (thus saving energy). DBS is just the same thing, but more tuned for monitoring server loading levels to make decisions on clocking down the frequencies as well as turning off multiple CPU cores/threads. Essentially, 'server-class' SpeedStep. The principle behind frequency under-clocking is manipulating the CPU's multiplier and since the low-end Xeons are already using the absolute lowest values possible, DBS is unavailable to these.
These Xeon processors however are just one part of the comeback equation, which Intel needed to fend off competition. However, the main proponent building the foundation for all of these server class processors and even those about to be launched is the new generation workstation/server class Northbridge chip, the Blackford Memory Controller Hub (MCH). Together, the Xeon 5xxx class processors and fresh motherboard level technologies made possible by the Blackford MCH, these form Intel's new generation dual processor server platform codenamed Bensley. More on the offerings that Blackford brings to the table, chipset variety and targeted segments are detailed on the next page.