FB-DIMMs, 771-pin Processors and moreIntel’s Skulltrail platform may be based around the custom made D5400XS motherboard, but there is a lot more that goes into a Skulltrail system than just that.
FB-DIMM 800 MHz Memory
First up, as we discussed on the previous page, the Intel 5400 MCH north bridge uses FB-DIMMs rather than standard DDR2 modules. At its most basic premise, FB-DIMMs differ from standard memory modules by the inclusion of a buffer between the memory lines themselves and the signals coming in from the controller. This buffer offers a serial interface to the modules that enables features like a larger memory “widths”, error correction on the module itself and data path redirection; unfortunately it does so at the expense of pure memory latency.
Intel provided a pair of DDR2 FB-DIMMs for our Skulltrail testing, rated at 800 MHz and at 2GB capacity each.
These Micron modules are CAS latency rated at 5; while not much higher than standard DDR2 modules available today it is slower than most enthusiast class memory quite considerably. Prices for FB-DIMMs are also higher than standard DDR2 memory but DDR2 has come down in price so significantly that this pricing issue is minor when compiled into a complete system.
Intel Core 2 Extreme QX9775 or Intel Xeon Processors
Don’t plan on taking that current Core 2 Duo or Extreme CPU you have now and moving it into your Skulltrail motherboard – it won’t fit. The workstation pedigree of the platform necessitates a move to LGA771 processors; more commonly known as Intel Xeon CPUs.
For Skulltrail though, Intel is in fact releasing a Core 2 Extreme branded processor that is in an LGA771 package – the QX9775. This quad-core, 45nm Yorkfield CPU runs at 3.20 GHz, has 12MB of L2 cache and runs on a 1600 MHz front-side bus. These specs are IDENTICAL to those of the QX9770 processor that we previewed last year with the only difference resting on the packaging of the cores.
To cool the processor, Intel sent along a pair of the now famous Zalman CNPS9000 series heatsink fans. Installation was a bit of a pain, mostly in attaching the mount to the motherboard, as I discussed on the previous pages but they performed admirably anyway.
Though there are four fewer pin connections on the Core 2 LGA775 processors, there are a pair PCB insets that will keep you from installing an incorrect processor on your Skulltrail motherboard. Notice in the two unmarked CPUs, the QX9775s, that there are semi-circular cut outs along the top; the E6700 shown here has the cut outs on the left side.
The Skulltrail motherboard and platform is being promoted as supporting both NVIDIA SLI and AMD CrossFire graphics technologies. That is indeed the case, but as I found out just last week, the SLI technology offered on Skulltrail is not all encompassing.
You won’t be seeing any of this…
AMD has told me they will be supported two-way, three-way and four-way CrossFireX on Skulltrail going forward as well.
Negativity aside, the ability to offer NVIDIA SLI support and AMD CrossFire support on the Intel Skulltrail motherboard is a big plus: users that don’t want NVIDIA chipsets can now officially “have it their way” so to speak. I tested both SLI and CrossFire in our gaming section so be sure to check that out for more details here.
Power Supply Recommendations
As you might have guessed, powering dual quad-core processors, dual or quad graphics and anything else you pile on the board, is quite a task. Intel is recommending that for a system with 8GB of memory, 4 GPUs and 2 CPUs that the user get a 1600 watt power supply or above. Umm…what? Have we even seen one of these yet?? (Actually, we have one in testing, but that’s a secret.)
With 2GB of memory, 2 GPUs and 2 CPUs, Intel says a 1000 watt or 1200 watt unit should do the trick. In our Skulltrail testing I used PC Power and Cooling’s Turbo-Cool 1200 watt unit and had now power issues at all. And in actuality, our system never used more than 640 watts of power even when running in SLI mode with a pair of 8800 Ultra cards.
eATX Chassis Recommendations
Finally, the case you put this all in needs to be built for the eATX spec if you want it to, you know, fit. Some of the more popular enthusiast cases are already eATX ready including the Cooler Master Cosmos 1000 and Stacker 830, as is the Thermaltake VA9000 and VA8000.