RIMM Voltage Should Be 2.5V, Not 3.3V

[LowLight76]

I'm using a P4 2.8GHz processor on an Asus P4T533 mobo; with a single 256MB Samsung RIMM4200. Here's my problem: Whenever I specify my FSB speed as 133MHz QDR (which makes my CPU run at it's default level of 2.8GHz and effectively makes my memory bus 1066MHz) my system locks up after about five minutes of doing anything CPU-intensive. However, when I lower the FSB speed to 100MHz QDR (which makes my CPU run at 2.1GHz and effectively makes my memory bus 800MHz) my system becomes perfectly stable. I've already verified that my memory module is indeed a 32-bit RIMM4200; also my CPU's temp never exceeds 105 F. Here's what I think is causing the problem: The 32-bit Samsung memory module is made to operate at 2.5V, not 3.3V. However, when I open then Asus Probe software in Windows XP it tells me that my current memory voltage is 3.344V, as opposed to 2.5V. I thoroughly checked the Bios and there's no where I change the memory voltage. I plan on calling Asus on Monday, but I was hoping to gather some input before then. Any information you guys can provide on remedying this problem would be appreciated. Thanks.

 

[mechBgon]

I've seen some pretty inaccurate voltage readings from Asus Probe on my systems, and I'd trust it as far as I could throw it when it comes to voltages. What RIMM voltage does the BIOS itself show, if you go in there and look?

edit: grrr, I hate having to hack Asus' site to get to a manual... :|

 

[mechBgon]

Also, sorry if this is way obvious, but do you have a C-RIMM in the vacant memory slot? If not, that's the first thing to try. What kind of power supply are you running it on, anyway?

 

[LowLight76]

Yeah, I have a C-RIMM installed. I'm using an Enermax 550W power supply. I switched the RIMM and C-RIMM to opposite slots, to no avail. Also, the Bios for the Asus P4T533 mobo doesn't show you the current memory voltage. I checked my User's Manual and it doesn't mention anything about memory voltage. As for the Asus Probe software, every other value that it's reporting seems to be accurate. The CPU and mobo temp, the rotational speed of all my fans, the CPU VCore; all that stuff is accurate under the Asus Probe software. I'm probably gonna end up getting my answer from Asus on Monday, but I wish I could find someone else who's having this same problem.

 

[mechBgon]

Hmm, if you wanted to get down and dirty, you could attack it with a voltmeter, I suppose. I've heard that most modern DDR modules have onboard VRMs to drop the actual chip voltage to 1.8V, and perhaps the individual IC's on your RDRAM are on the other side of VRMs too *shrug*

Good luck, anyway. That's a rare beast so I don't know how good your chances are of hearing from another owner, but it might help to put "P4T533" in your thread title to attract their attention.

 

[colonel]

Asus Probe doesn't give a exact number, you can download the free Sandra and ckeck