8GB DDR2-800 and Vista - Road to 8GB and Test System

Article Index
8GB DDR2-800 and Vista
Crucial and Patriot DDr2-800 Kits
Road to 8GB and Test System
Synthetic Memory and Game Benchmarks
Real World 8GB Gaming Results
Applications and 8GB DDR2 on Vista

The Road to 8GB:

One thing that I have learned in this review is that just because a motherboard claims that it supports "Up to 8GB of DDR2" doesn't mean that it will work very easily.  We had a fairly current BIOS on our MSI 975X Plantinum V2 board, but every time we tried to boot with more than 2GB of memory we'd get an nVidia Graphics Driver related error.  Booting would yield a BSOD and an error related to the following - nvlddmkm.sys.  I searched the web for a solution and discovered that many people that had this issue were using 4GB of DDR2.  I found an updated BIOS (that wasn't there when I initially received the memory) and flashed the BIOS to relieve my trouble.  After that, things when much more smoothly with either 4GB kit installed.

We ran benchmarks with both kits, as you'll see in a few moments, then proceeded to attempt an 8GB Vista OS by dropping both 4GB kits in at the same time.  The specs are fairly similar, and both kits rand solid at stock speeds, but when we tried running with 8GB installed we ran into another caveat.  Vista 64-bit now only identified 2GB of RAM!!

2GB Vista
2GB Vista


Although it appears to be somewhat unrelated, Windows identified all 8GB of memory when I enabled HPET support in the BIOS.  HPET has to do with Multimedia timers under Vista and seems to have more to do with the video subsystem - regardless, this resolved our issues and we were 8GB happy!

8GB Vista
8GB Vista


Although we had already overcome a few issues, there were more to be had when running 8GB of memory in our system.  To help understand our trouble populating all four DDR2 slots with their own 2GB stick of memory, we need to refer to some CPU-Z screenshots about the timings of each memory kit.

CPU-Z Crucial
CPU-Z Crucial
 CPU-Z SuperTalent
CPU-Z SuperTalent


If you take a look at both screenshots above, you'll notice that the Crucial 4GB kit of PC2-6400 comes with SPD timings set at 4-4-4-12 for DDR2-533 and 5-5-5-18 for DDR2-800.  The SuperTalent PC2-6400 kit is a different story.  While the label clearly states that the kit is a DDR2-800 kit, the memory is actually identified internally as a PC2-5300 or DDR2-667kit.  The SuperTalent kit has memory SPD profiles of 3-3-3-8 at DDR2-400, 4-4-4-11 at DDR2-533 and 5-5-5-13 at DDR2-667.  There are no SPD settings for DDR2-800.  That may post a problem when trying to run them together.


With all four sticks installed we set the timings at 5-5-5-15 in the BIOS and managed to boot into vista at DDR2-800 at 1.85v, but when we checked CPU-Z to verify our memory settings we discovered that we were running at 5-5-6-15.  No matter what we set the RAS Precharge time to in BIOS, it would always show up with a value of 6.  I guess we can't complain as I'm sure this is somewhat uncharted territory.

 CPU-Z Timings
CPU-Z Timings


Test Info:

Due to the lengthy time we've had this memory and have been waiting for BIOS updates, it's important to notice the test setup below.  We have ran all of these memory kits at their fastest possible speeds - except for the Patriot kit, which we ran at the same speed as the 4GB Super Talent kit for a direct 2GB - 4GB comparison.  When running 8GB of memory, we were not able to overclock a mere 5MHz with rock stability, so the 8GB benchmarks are in fact ran at completely stock speeds.  All the other information is posted below.


Test System Information


Intel Core 2 Quad Q6600 - MemoryExpress


MSI 975X Platinum PowerUp! Ed. with BIOS


eVGA 8800GTX 768MB - MemoryExpress

Memory Setup #1:

2GB Patriot PC2-6400 "Eased Latency" DDR2-800 at 5-5-5-12 DDR2-813
CPU @ 9*271=2.44GHz

Memory Setup #2:

4GB Crucial PC2-6400 DDR2-800 at 5-5-5-12 DDR2-840
CPU @ 9*280=2.53GHz

Memory Setup #3:

4GB SuperTalent PC2-6400 DDR2-800 at 5-5-5-13 DDR2-813
CPU @ 9*271=2.44GHz

Memory Setup #4:

8GB consisting of both 4GB kits listed above at 5-5-6-15 DDR2-800
CPU @ 9*266=2.4GHz

Operating System:

Windows Vista Ultimate 64-bit

Memory Usage on First Boot:

  • Setup #1 - 644MB = 31% Used
  • Setup #2 - 1.02GB = 25% Used
  • Setup #3 - 1.01GB = 25% Used
  • Setup #4 - 1.17GB = 14% Used


Naturally, we expect the fast CPU speed to increase performance, but we wanted to show what was possible with both 4GB and 8GB based systems.  Keep the CPU speed in mind as we carry on through this review.  Also keep in mind that both 4GB kits and the 8GB kit is at it's maximum stable clock speed.  These numbers show the maximum memory performance.

On the next page we'll jump into the benchmarks.