Need advice on dimm compatability

[youngtrotsky]

Previously one 512mb ddr400 stick installed, just got 2 more sticks (also 512mb ddr400) from a friend who's pc packed up on him. The new sticks are a different brand and have CL of 3.0 whereas my stick has 2.5. When all 3 sticks are installed the PC crashes within 10-30 minutes of boot (monitor goes blank and displays "input not supported" but pc is still running, has to be restarted to get anything back on screen), but any combination of 2 sticks works fine. I assumed that this means the sticks are compatible and all work but am confused as to why all 3 won't work together. I am by no means an expert on this as am sure you can tell and was hoping for any advice you could throw my way. Cheers.

P.S. my mobo is asus k8v se deluxe and should support 3gb of this memory so that shouldn't be the problem.
P.P.S. "works fine" means Prime95 found no errors after 1.5 hours torture test

 

[XMSYellowbeard]

You may need to raise your DIMM voltage a bit if you have not already. Try 2.65v - 2.8v, somewhere in that range should be fine for most DDR.

Also, what you are describing "could" be a power related issue. What PSU are you using?

 

[youngtrotsky]

Thanks for reply, I tried upping the voltage to 2.8v, the highest my BIOS would let me, the system lasted around 30-40 minutes but then crashed as before. My PSU is 450w, do you think a more powerful one is necessary?

 

[XMSYellowbeard]

It's not necessarily the overall wattage rating but, the quality and also rating on specific rails. Can you list the individual rail specifications and any other info you have on it.

 

[youngtrotsky]

OK just reading the label on the side of it:
+12V 20A max
+5V 38A max
+3.3V 28A max
-5V 0.5A max
-12V 0.8A max

+5V/SB 2.0A max

Is that the info you wanted?

 

[XMSYellowbeard]

Yeah, that is the main info I needed. Depending on what video card you have and how many peripherals you have, your 12v rail may be too weak. I'm not 100% sure of course but, since all of your memory appears to work, that is my best guess based on the info we have.

 

[youngtrotsky]

That seems to be it, I've just replaced the radeon 9800 pro with my old 9250 (no fan) and it all seems to working now. Thanks for the help I guess I'll just have to decide whether to buy a new psu or sell the 9800 now!

 

[XMSYellowbeard]

Well, at least you know what your options are now. It is a tough spot. If you decide to go the PSU route, I'd suggest something robust so that you can use it on future builds. And, if you are a gamer, I can imagine you don't want to give up the 9800.

 

[youngtrotsky]

OK new problem! With the 9250 I now get a different type of crash. Instead of the monitor going blank and saying input not supported I now get a blue screen with MACHINE_CHECK_EXCEPTION at the top and *** STOP 0x0000009C (more zeros and letters in parentheses).

Does that also sound like a power related issue? The blue screen says that new hardware/software could be the problem so it's obviously the same issue.

 

[XMSYellowbeard]

I'd test it with any 2 DIMMs (if you have 2 that match use them) and see what happens. It may just be the MOBO and memory controller. You may actually end up running 1gb (2 x 512mb) and the 9800 together.

 

[youngtrotsky]

Yeah I already tried that, any 2 work fine with either graphics card it's only when all 3 are installed that the pc crashes, blank monitor with 9800 and blue screen with 9250.

 

[Mondoman]

It would help a lot if you would list the model numbers of every component, including things like the CPU, PS, memory, video card, etc.

 

[youngtrotsky]

CPU: Athlon 64 3400+ clawhammer
Mobo: Asus k8v se deluxe
GFX: ATI radeon 9800 pro 128mb
PSU: Win Power ATX-450
RAM: 2 sticks Nanya 512mb ddr-400 + 1 stick Geil 512mb ddr-400

 

[Mondoman]

What are the model numbers of your RAM?

 

[youngtrotsky]

Geil stick: CL25-3-3DDR 400
Nanya sticks: M2U51264DS8HB3G-5T

 

[youngtrotsky]

So, did that help? I got a new PSU with 23A max for +12V1 and +12V2 but the problem is still there. I also just noticed that when all 3 sticks are installed CPU-Z says RAM speed is 129.6mhz instead of 200mhz when only 2 sticks are installed, the CPU:RAM multiplier is 17 instead of 11 :S No idea why this is I didn't change any settings.

 

[Mondoman]

Sounds like it could be a MB problem. The downclock with 3 sticks is a common "feature" on such motherboards; basically, they are so close to the edge that they can't handle full speed with 3 sticks installed, so they downclock to make things easier. My guess is that your specific MB just can't handle 3 sticks.