1 year old PC failing CRC checks, possible RAM issue?

ljay880

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Hello everyone,
I built a PC a bit over a year ago, and all has worked great till the last 30 days. When first built, I ran Memtest and let it do 7 passes, and no errors were detected. About 30 days, I started getting CRC errors when compressing/uncompressing files, and just opening downloaded .RAR files (corrupt & failed the CRC). It was very minor at first, but has since increased in severity/regularity. I thought that it might be the memory, so I decided to run Memtest 4.10. I get tons of errors. Since I have two sticks, I pulled the one out of the second slot and tested. No errors, so I assumed the second must be bad. I pulled the stick from the first slot, and replaced with the one I had previously pulled. There was one single error, during the first pass one test 4, but the next 3 passes didn't turn any errors. Since my board has 4 slots, I put the two sticks in the 2 slots I had not previously used just to see what would happen. I got a single error during the first pass, on test 2. However, that was the only test to fail at all and when using the other 2, I failed many instances through every test on the pass. During the second pass, the single error on test two did not repeat. I am confused on what to try next here, or what happened, but I really want to get the PC back to normal. I have a decent background in computers, but I have never really been in to over-clocking and am not really that knowledgeable on memory timings/settings ... which is why I leave everything at default/auto-detect. I hope somebody has some insight to my problem. My build is as follows:

Mushkin Enhanced Blackline 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model 996599

GIGABYTE GA-EP45-UD3R LGA 775 Intel P45 ATX Intel Motherboard

Intel Core2 Quad Q9400 2.66GHz LGA 775 95W Quad-Core Processor BX80580Q9400
 

cpatel1987

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The single error might just be a fluke. One thing to try is to check the voltages of the RAM in the BIOS. Your RAM should be in the 2.0 - 2.1V range according to your RAM specs. Anything else, undervoltage or overvoltage, I believe would cause errors over time (I've heard mixed things about this, correct me if I'm wrong), that is, if your running the RAM at 1066.

Also, did you run Chkdsk? If not, would rule out hard drive issue. Of course, back up any important data you may have first.
 
Core2 motherboards set DDR2 RAM to a default 1.8 volts. If the factory recommended voltage is 2.1 volts, you need to go into the BIOS, take your RAM voltage off Auto, and set it to "Default + .3". If that doesn't work, go to "+.4" (2.2 volts).
 

ljay880

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I will try the Chkdsk, but I do have a question about the RAM voltage. The memory is running at 800, despite being capable of 1066. The reason for this is that my motherboard is finicky about making 1066 work, and it will not boot unless dialed in just right (it might not even post if I remember correctly). I had to take it into a shop after building it because I was just stumped. The guy there grabbed an 800 stick, and put it in with mine. It posted and booted right up, the auto settings dialed it in to work with the 800, then he shut it down and pulled the stick. After that, it has always worked great, till now that is, but the RAM has never run at the 1066. I do not have another stick to pop in if it doesnt like my settings I try, so I just never messed with it. Does the voltage make a difference if it is not running at 1066?
 

cpatel1987

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The frequency you use typically does correspond to the voltage. If you are using it at 800, AND the voltage readings in the BIOS are 1.8 ish V, then it should be fine. I had a similar problem with my 2x2 GB DDR2 Ballistix that run at max 800, but because my motherboard doesn't allow me to change the voltages, I actually had to go even one step down from 800. I never got CRC's, but instead got IRQ not less or equal BSOD's. It would be more ideal to match voltages so you don't have to step down even further. Again, reason why I stated correct me if I'm wrong is because I'm just basing this on my own experience, where again I stepped it down to 633 and haven't had a problem since.

So in short, my answer is I'm not 100% sure if voltage output of the RAM corresponds to the frequency it operates on, but based on my situation it worked.