Trying to use 2 sets of G.Skill F2-8500-4GBPK (8GB Total) at 1066mhz on Asus P5K-E

[fl62]

Cannot use 2 sets of G.Skill F2-8500CL5D-4GBPK (8GB Total) at 1066mhz on Asus P5K-E

I have 2 sets of G.Skill F2-8500CL5D-4GBPK running on an Asus P5K-E for a few years now. The Ram were both purchased new from NewEgg, and are very close in serial numbers (Set#1 ends in xx17 and xx18, while set# 2 ends in xx22 and xx23).

It has worked flawlessly on this board at DDR2-800 speeds and 4-4-4-12 timings (vDimm 2.0v) on a Core2 Q6600 this whole time.

However recently I upgraded the CPU to a Core2 Q9650, ans decided to turn up the Ram speed to the rated DDR2-1066 and stock 5-5-5-15 timings (vDimm 2.1). It will post and boot into windows, but is plagued with memory errors and BSOD's. It will also fail memtest quickly.

I have tried a number of obvious things (one at a time to systematically test), such as raising the vDimm as high as 2.4v, raising the NB voltage to 1.4v, raising the FSB Termination voltage as high as 1.4v, and of course relaxing the timings as low as 7-7-7-15. Each was done in small increments.

I have also tried the three last BIOS versions for this board (older than that does not support my new CPU) 1102, 1202, 1305

I have read many threads on this forum of users having poor luck on various different motherboards and being successful running this RAM at 8gb AND DDR2-1066.

Of course the problem is that this kit is NOT sold in an 8gb set (Maybe this is why?)

I have tried each set separately (4gb Total) at DDR2-1066, and all works fine. It seems that the two sets are just not compatible when running at 1066 speeds and 8gb installed.

I have another 8gb kit of G.Skill F2-6400CL5D-8GBPK running in my Dell Precision Workstation, and it is perfect.

Is there any solution to getting more memory bandwidth out of my aging system without going to DDR3? At that point it is a whole system upgrade, which I am trying to avoid.

Thanks

[Tradesman]

Might be the BIOS doesn't set the sticks properly in the advanced timings, notably the tRFC may be off, with that, may just have to play with it, will see if I can dig up some appr timings that might help, what are your current advanced or secondary timings

[fl62]

The timings that are troublesome are 5-5-5-15-3-52-6-3-3 2T at 1066mhz at any reasonable voltage on the vDimm and NB Voltage. tRFC is 52

I am currently back down to DDR2-800 at 4-4-4-12-3-52-6-3-3 2T at 2.00v vDimm

[Tradesman]

My try taking tRFC up to about 88 just to see if it helps

[fl62]

Thanks for the suggestion Tradesman...

Unfortunately, still no luck.

Tried tRFC at 85, and 105 with vDimm at 2.1v, 2.2v, 2.3v, and 2.4v
Also tried 6-6-6-18 Timings with the above tRFC settings and voltages. Always errors out on Memtest within first 10-15%

Thanks

[Tradesman]

May be time for a RMA

[fl62]

Thanks for trying to help tradesman!

I'll contact G.Skill and see what we can do.

[Tradesman]

Keep us updated

[fl62]

Sure will - just sent in the RMA form.

[Tradesman]

We'll be waiting to hear