Stability Problems Asus Blitz Formula & 4GB Dominator PC-9136 C5

[Jambo]

I have been struggling with my vista x86 crashing (Rebooting) with 4x1gb Dominator Twin2X2048-9136C5D memory installed. I have tried three different motherboards (2 x asus blitz formulas & Abit IP35 Pro) all showing the same issues. I also know that I need 64 bit vista to utilise more than 3.2gb but 3gb of memory is fine for me so want to keep with 32 bit vista.

 

I am currently running with the following :-

 

Asus Blitz Formula (also updated bios to latest version)

Intel QX6850 3GHz processor

PC Power & cooling 1kw psu

3 x WD raptor 150 in raid 0

2 x Hitachi 1tb drives.

 

The FSB for the processor is set to 333

The Dram FSB is set to 266 running the 4x1gb modules at 1066Mhz @ 2.1v set to 5-5-5-15 2T

 

Both sets of memory appear to run fine on there own (2x1gb in total) but as soon as I add the 2nd pair of 2x1gb modules (total of 4gb) the system will crash at random, this can range from days to minutes. Vista runs ultra stable with only 2gb installed.

 

Memtest+ V1.70 will pass both sets of modules on their own but as soon as all 4 1gb modules are installed memtest will fail at random memory locations.

 

I have tried the following :-

 

NB to 1.45

Dram voltage to 2.2

 

The Asus bios also has the following bios options which I'm not used to, perhaps some one could explain what these are for ontop of the dram voltage setting :-

 

Dram controller Ref voltage (settings + or - 30mv)

Dram channel a ref voltage (settings + or - 30mv)

Dram Channel b ref voltage (settings + or - 30mv)

 

I have been fighting this problem for a few months now and really have run out of ideas. so hopefully someone here has experienced the same or similar problems and can point me in the right direction.

 

 

 

Thanks

[RAM GUY]

With 4 modules I would set the memory frequency at DDR800 and please test them one set at a time at their tested setting to make sure one is not failing.

[Jambo]

Both sets of memory have been tested on their own and work perfectly @1066. Both Pass memtest (13 hours + 39 passes) and vista is 100% stable.

 

Why do you suggest running them at 800 and not 1066. I purchased them to run at 1066 :question:

[RAM GUY]

There is more loading on the system with more memory and sometimes that may be required, bottom like if they run as they are sold one set at time at their tested settings its not the memory.

[DerekT]

Both sets of memory have been tested on their own and work perfectly @1066. Both Pass memtest (13 hours + 39 passes) and vista is 100% stable.

 

Why do you suggest running them at 800 and not 1066. I purchased them to run at 1066 :question:

 

The issue is not the DRAM Jambo. The issue is that mainboards are at this time not optimized for 4GB. The chipset memory controllers have to work harder with more denser modules and double the DRAM means that there has to be a longer que to await the data delivery. A longer que means that it will take longer for the data to be accessed and this means that the columns and rows need to be open longer which means that you need to slow down the DRAM somewhat.

 

This is one of the reasons for DDR3 DRAM. The latencies are much higher than DDR2 which allows for denser accesses. The problem is not the DRAM, the problem is that mainboards are not yet fully optimized for 4+ GB in high speed, low latency configurations.

[Jambo]

Thanks guys for the information I guessed it wasn't the memory.

 

Without running the memory at 800FSB what timings do you suggest I try and is this likely allow me to use the memory?

[RAM GUY]

You just have to test the system, but you might get them to run at Cas 4-4-4-12.