Problems with DDR2-1066 Memory on ASUS P5KC Motherboard

[RobK88]

Hi,

I gave been trying to get some Crucial memory DDR2-1066 CL7 memory to work on my ASUS P5KC motherboard. I have updated the BIOS to the latest version 1203 and done a CMOS reset.

I have four 2 GB memory DIMMs. Tested the RAM. All pass HCI memtest at 1066 at CL7 timings BUT only if I use 2 memory slots (i.e. 4 GB max). (I tested all the memory -- but only two memory DIMMS at at time).

When I try fill all the memory slots (ie 8 GB), the HCI memtest shows errors.
I tried increasing the DRAM voltage from 1.8 to 1.9 volts. But I got even more errors.

But when I drop the speed to 800 and use CL6 timings, HCI memtest shows NO errors when all the memory slots are occupied (ie 8 GB total)

My initial conclusions:

1. None of the DDR2 RAM is defective.
2. None of the memory slots/connectors on the motherboard are defective.
3. I probably have a bad motherboard or memory controller.

Questions:

1. Are my conclusions above reasonable?
2. Can you think of any BIOS tweaks that might make the DDR2-1066 memory actually work at 1066?
3. Should I try running the DDR2-1066 memory at 800 with CL5 or CL4 timings? (It does work at 800 with CL6 timings). If yes, what EXACT timings should I use?

Any assistance or ideas would be greatly appreciated.

Rob

 

[RobK88]

These boards would often only support ddr3 speed dimms at 4 gig or less.
If you look at the era 800 meg was plenty. Running at 1066 will not improve performance with 8 gig in the board as the fastest cpu's that would run in it even overclocked would only need 400 meg front side bus speeds (ddr800) for e.g. an overclocked 8 series duo (fsb 333 at stock). Increasing beyond this really only has the effect of increasing volume as the cpu/ram multiplier alters. In other words, 8 gig at 1066 would be like having 10 gig at 800. Performance in programs that dont use that much would be unaffected and the cpu and northbridge chip is likely going to bottleneck performance anyway.
I doubt you would have any luck with cas 4, but 5,5,5,15 was common with 800meg hi end ram.
I can only stress again just getting it running with 8 gig is enough.
The bottleneck will be the northbridge chip and the cpu.
I cant open this at the moment, I am having an argument with 7 zip but feel free to look.
http://www.asus.com/uk/Motherboards/P5KC/HelpDesk_QVL/

Yes the P5KC only supports 4 GB of DDR3 RAM.
But it is supposed to support 8 GB of DDR2 RAM.
In any event, it sounds like there will be little (or no) improvement running the DDR2 RAM at 1066 vs running them at 800 speed.
But it should be faster if I can get CL5 latency. I will try 5-5-5-15 as you suggest.

 

[RobK88]

These boards would often only support ddr3 speed dimms at 4 gig or less.
If you look at the era 800 meg was plenty. Running at 1066 will not improve performance with 8 gig in the board as the fastest cpu's that would run in it even overclocked would only need 400 meg front side bus speeds (ddr800) for e.g. an overclocked 8 series duo (fsb 333 at stock). Increasing beyond this really only has the effect of increasing volume as the cpu/ram multiplier alters. In other words, 8 gig at 1066 would be like having 10 gig at 800. Performance in programs that dont use that much would be unaffected and the cpu and northbridge chip is likely going to bottleneck performance anyway.
I doubt you would have any luck with cas 4, but 5,5,5,15 was common with 800meg hi end ram.
I can only stress again just getting it running with 8 gig is enough.
The bottleneck will be the northbridge chip and the cpu.
I cant open this at the moment, I am having an argument with 7 zip but feel free to look.
http://www.asus.com/uk/Motherboards/P5KC/HelpDesk_QVL/

Yes the P5KC only supports 4 GB of DDR3 RAM.
But it is supposed to support 8 GB of DDR2 RAM.
In any event, it sounds like there will be little (or no) improvement running the DDR2 RAM at 1066 vs running them at 800 speed.
But it should be faster if I can get CL5 latency. I will try 5-5-5-15 as you suggest.

I forgot to add one important detail. The ONLY way I could get 4 GB of the Crucial DDR2-1066 memory to run at 1066 is by setting the DRAM voltage manually in the BIOS to its design voltage of 1.8 volts. The AUTO setting in BIOS did not work.

If you want to get 8GB of DDR2-1066 RAM to work. Good Luck. I has to drop from 1066 to 800 to get 8 GB of DDR2 RAM to work reliably according to HCI memtest. As pointed out, it is likely the crappy chipset on the ASUS P5KC motherboard which is to blame.

So if anyone is having trouble getting DDR2 (or DDR3) RAM to work on the ASUS P5KC Motherboard, you may want to try setting the DRAM Voltage manually in BIOS to the design voltage for the RAM in question.

Rob