Do-It-Yourself Quad-SLI: It's Official
Quad-SLI Components: Memory & Misc.
Another major component to a Quad-SLI system is RAM. To coincide with the launch of the nForce 500 family of chipsets, NVIDIA also announced support for Enhanced Performance Profiles, or EPP. EPP is a feature designed to maximize system performance by automatically tweaking memory and CPU frequencies, multipliers and voltages on compatible motherboards.
EPP is a new open memory standard that was co-designed by Corsair and NVIDIA and adopted by a number of motherboard and memory manufacturers. Enhanced Performance Profiles can increases performance by taking advantage of additional memory parameters added to the unused portion of a standard JEDEC Serial Presence Detect, or SPD. The JEDEC specification only calls for small amount of data to be stored in a standard SPD, which leaves a significant amount of unused space. EPP takes advantage of this space to store specific information about the modules, like their maximum supported frequencies, recommend voltages and timings.
EPP also needs motherboard support to function as well. To support EPP a motherboard's BIOS has to be programmed to snoop the upper portion of the SPD to find the EPP relevant data. That data is then used in conjunction with a pre-determined set of parameters stored in the system BIOS to automatically tweak performance.
For example, if the EPP data stored in the SPD states a particular memory kit is capable of running at 1066MHz with 5-5-5-12 timings, EPP will automatically alter the processor's multiplier, voltage and bus speed, along with the memory voltage, to get as close to said memory's rated speed as possible. EPP will also overclock the processor by a user determined percentage to hit the memory's rated speed.
The Asus P5N32-SLI SE Deluxe that we used as the basis of our Quad-SLI build does not have support for EPP, but upcoming nForce 590 SLI will. Although any memory will work in a Quad-SLI system, EPP equipped memory is usually of high quality and we recommend considering it. The rig we put together was equipped with a 2GB Corsair TWIN2X2048-6400C3 DDR2 memory kit capable of DDR2-800 speeds with relatively tight timings of 3-4-3-9.
For the rest of our Quad-SLI system, we used an HSPC Tech Station (case), an LG DVD-ROM drive, and a Western Digital WD1500 Raptor hard drive. NVIDIA doesn't make any specific case or optical or hard drive recommendations. However, we can speak of some of our own general recommendations based on our experience. In regard to storage, your preferred brands / models will be fine. Just ensure motherboard compatibility as some Maxtor hard drives had a known incompatibility with nForce chipsets. As for the case, we'd recommend mid- or full-tower enclosures that have oversized intake and exhaust fans and preferably a vented side panel. Having four GPUs and 2GB of fast GDDR3 memory in a system means there will be plenty of heat generated, and that heat has to be considered. Consider good ventilation an absolute must.