Compatibility & Diagnostics

[foxfyre841]

Hi All,

Thought I would start a thread that could help people (and myself) along the lines of learning the different diagnostic tools available. I'll even be a guinea pig. My current rig is listed in my user system spec sheet. I recently had a problem when I mixed two different ram.

 

twin2x2048-6400c4 rev6.2 and twin2x2048-6400c4dhx rev2.1

 

I would frequently get blue screens when both were installed (page fault in non-paged area, & etc).

I had the ddr-voltage at 2.1

and the timings manually set 4-4-4-12

with 800mhz and 2T.

 

This was unstable in the operating system. However it would pass memtest 9 times with no errors as installed. Because it wasn't working in the operating system, I downgraded to the 667 instead of 800mhz. This has so far proved stable. What should I do next or what information would you need to determine how to bring the system back to 800mhz?

 

Thanks!

[DerekT]

The problem in this case is clear. Memtest passes because the memory is allowing load and access of the memory without errors. In this data stream you have CPU <--> Memory Controller <--> Memory. The memory is isolated. If you test the CPU with a fresh install of Windows and LinX and pass the test, then you have dealt with the CPU test. You have now isolated the memory and the CPU. What's left is the memory controller and this is commonly where issues will occur when you run all four DRAM slots at the full speed of a two module kit.

 

The only memory Corsair supports in a four DRAM slot population is their Quad kits. This does not mean two dual kits or even worse two dual kits of different versions will not work together, just that you have no recourse to RMA Corsair if they do not work together. If there are problems with the DRAM modules, they are still supported via lifetime warranty, but that is for physical defects and errors in a two stick kit mode. Matched Quad sets are highly binned modules for a four slot population. The Dual sets are tested as a kit, not a Quad and warranted as a dual kit, not a Quad setup. You need to Memtest them as Kits (2 modules, not as a four DRAM slot population). If they fail as a kit or singly, then you have RMA. Keep in mind that there is no support for mixing and matching different versions of DRAM either since different version are of different fabrications and/or manufacturers. They might work, they might not work, but you have no support if they do not work. Thus you are advised to buy all the DRAM at the same time and in this way be more assured of getting the same versions. If you buy online, be sure to specify same versions of the modules.

 

You are advised to drop the speed of the memory to 667Mhz and raise the memory controller voltage +.2v (+.1v for X38/X48/P45).

 

Please research this thread:

 

http://www.houseofhelp.com/v3/showthread.php?t=64360&highlight=Unpredictable+results+QUAD2X4096+Gigabyte+X38-DS5

 

There is a limitation of the On Motherboard (Intel) memory controller or On CPU (AMD) and a population of all four banks at the full speed of a two bank run. This limitation is across the board with both AMD and Intel chipset based boards, DDR, DDR2 and DDR3.

 

Keep in mind that often issues can arise in the longer term even though you have shorter term stability. The issues seldom damage the DRAM unless you raise the DRAM voltage too high. They damage the on CPU (AMD or i7) or on motherboard (Intel) memory controller which has a harder time keeping up with the demands of a four DRAM slot population being run as fast as a two DRAM slot population.

 

Now, that being said, the overclocker can increase the CPU FSB which concurrently increases the MCH and helps you regain lost bandwidth as the memory speed increases. Please research the given thread for that information.