I'd like some help knowing if I bought the wrong RAM or I'm just getting hit with a random incompatibility.

My current config:
MSI P6N SLI Platinum
2x1GB Crucial Ballistix DDR2-1000 DIMMs, 2.2V

Everything works fine now, but I wanted to up to 4GB for some virtual machines to perform better. So I bought a corsair 2x2GB DDR2-800 pack. My motherboard states it will support up to 8GB in 4 slots, and the BIOS is reporting all 4GB. However, when I boot Vista, it reboots during the boot cycle. Memtest x86 freezes early on in testing, as does Vista's memory test tool. I updated the BIOS, and set the RAM voltage from auto to 2.10V, but no luck booting.

I'd just like to know for my own education if I missed a spec for compatibility, or if this is just one of those days.

Thanks

Adam

***EDIT: Just to clarify, I am removing the old Crucial sticks and using just the 2x2GB Corsair RAM.

Try upping the voltage a little bit.

Agree. If the Crucial wants 2.2 then you probably need to give it 2.2. What is the Corsair rated for? You may also want to try upping the timings and reducing bus speed to RAM. Try 667 instead of 800.

Getting 4 sticks to work can require some speed reductions on many MOBOs. Keep tweaking.

Of course it's also possible you got a bad stick. See if the Corsair will run stably by itself.

It's probably 'random incompatibility'.
Run the memory seperate to check or maybe the board doesn't like feeding 2.1v to 4 dimms.

4 sticks can be touchy to get running, let alone 2 sticks of one brand and 2 sticks of another rated a different speeds. You may not have got the "wrong" memory, but you have compounded the problem by buying a different brand and type of memory to mix with what you already have.
You board may be "confused" because now it has 2 different types of memory telling it to default to 2 different settings at the same time.
Enter your BIOS, turn off the auto-detect features for the speed/timings and voltage. Set everything to the speed of the slower set, and 2.2 on the voltage. See if it will boot then.

Sorry - let me clarify; I'm removing the old sticks and just going with the 2x2GB sticks of the Corsair, so that I don't have to deal with mixing different types of RAM.

Adam

Ah, will it boot with only 1 stick of the new memory?
If it will, try them both seperate. Could be an outside chance 1 of them is bad, maybe.....

RAM above DDR2 800 (ire DDR2 1066) are known to have compatibility issues, esp. with P35 chipsets.

As jtt wrote, try testing the ram one stick at a time. This does sound like a ram failure. Also, you might double check that you have the ram sticks pushing all the way into their sockets. I've had it happen to myself that I pushed the ram stick in, but it wasn't completely seated and the machine wouldn't boot. Upon inspection, I found one stick not all the way in. Reseating it cured the problem.

Yes, do check the motherboard manual for ram compatibility, but sometimes it can just be "one of those days".

Well, son-of-a-****... seems to be good old fashioned DOA stick. One of them works fine by itself. Time to RMA to newegg.

Thanks for all the tips... I don't really do much system building anymore, and was pretty much convinced that I missed something in the specs before I did as thorough of a job troubleshooting as I should have. I'll swap it with a new set, and will (hopefully) be good to go.

Thanks again!

Adam