In the current server-class arms race, Intel and AMD have secured separate quarters: Intel’s rival QPI architecture coupled to a 3-channel DDR3 memory bus and functional hyper-threading cores (top bin parts) holds the pure performance sector; while AMD’s improved Istanbul cores can be delivered 6 at a time and paired with inexpensive DDR2 memory to achieve better price-performance (acquisition). Both solutions deliver about the same economies in power consumption under virtualized loads.
All in all, the Twin2 with Xeon L5520 CPUs is the best platform for those seeking an affordable server with an excellent performance/watt ratio at an affordable price. On the other hand, if performance/price is the most important criterion followed by performance/watt, we would probably opt for the six-core Opteron version of the Twin2. Supermicro has “a blade killer” avialable with the Twin², especially for those people who like to keep the hardware costs low.
Meanwhile, the cost differential between DDR3 and DDR2 continues to widen due to increased demand in the notebook sector and reduced supply (capacity). According to DRAMeXchange, the trend will continue into Q4/09 as suppliers are expected to commit up to 30% of capacity to DDR3 by that time.
At the same time, DDR3 prices continue to inch up, by 5% in July, while DDR2 prices have appeared to bottom-out. This trend in DDR3 pricing is consistent across all speed ratings (1066/1333/1600) and, despite artificial downward price pressure from Samsung, has managed to drift upward 20% since May, 2009.
Because low-end, lower-priced 2GB DDR3/1066 ($60/stick) memory shows little advantage over 2GB DDR2/800 ($35/stick), the 70% price premium keeps DDR2 in demand. With the added economic pressures of the world economy and cautious growth outlook of manufacturing sector, the cross-over from DDR2 to DDR3 will come at a significant cost: either to the consumer or the supplier.
Until the cross-over, DDR2-based systems will continue to be a favorite in price sensitive applications (i.e. where total system cost plays a significant role in purchasing decisions.) As an example of this economic inequality, let’s take the HP DL380 G6 and DL385 G6 as a comparison. Adding 16GB to the DL380 adds about $760 to the price tag (4x4GB DDR3-1066), while adding the same amount of memory to the DL385 adds only $410 (4x4GB DDR2-800). This comparison demonstrates an 85% price premium of DDR3 versus DDR2, a bit higher (percentage wise) than the desktop norm of 70%.
SOLORI’s Take: While the cost of memory in desktop systems typically represents a small portion of the overall system cost, the same can not be said for virtualization systems where entry configurations weigh-in at 16GB and often run from 48GB to 72GB in “fully loaded” systems. This, as our calculus has shown, is where the sweet-spot of $/VM is delivered.
In such configurations, the cost of DDR3 memory can tripple the system cost ($6,370 for 2P, L5506 w/12x4GB DDR3-1066R vs. $5,201 for 2P 2427 w/12x4GB DDR2-800). Moving to the higher memory footprint in 2P systems is typically not cost effective because core count cannot keep-up with the memory needs of the virtual machine inventory. However, if it were possible to utilize additional memory in the 2P platform, our benchmark 8GB DDR3-1066 versus DDR2-667 price comparison tells another story. At $900/stick, the cost of 8GB DDR3 is still a 235% premium over 8GB DDR2, making 96GB DDR3 systems (2P Xeon w/HT) nearly $6,200 per server more costly than their DDR2 counterparts (2P Istanbul) based on memory pricing alone.
SOLORI’s 2nd Take: We’re hoping to see Tyan and Supermicro release SR5690 chipset-based systems – promised in Q3/2009 – to take advantage of this pricing trend and round-out the Istanbul offering before Q1/2010 ushers-in the next wave of multi-core systems. With 10G prices on the decline, we think today’s virtualization applications make Istanbul+IOMMU a good price-performance and price-feature fit in the 32-64GB memory footprint space, leaving Nehalem-EP with only the performance niche to its credit. The only question is: where is SR5690?