Set the voltage to auto or 1.5V asap.

Which asrock mobo?
Which slots are you using right now?

Both of them. The mobo should be in my Speccy.

edit: just loaded in with the 1.5V setting, doesn't seem like much has changed.

Wasn't expecting anything to change, it just shouldn't be running at 1.65V.

I'm suspecting that the mobo is trying to use Dual Channel even though the DIMMs aren't the same size.

I'll have to read the manual so please be patient.

It's fine, I've got time.

Haven't found anything yet.

Have you already tried booting with only one stick (sorry if I missed the answer to that one)?

No, I'm really fucking scared of messing with that thing again considering every time I do something to it my PC's performance degrades.

Don't worry, it won't explode and you can always but that stick back in.

All right, I booted with the 4GB stick and no improvements. Booting with just the 2GB stick

Booted with just the 2GB stick. No improvement

i had a very similar problem and i'm really hoping this will solve it for you

when this happened to me, it was a usb conflicting driver error. it started happening when i got a new mouse (i think anyway). I switched around which ports my keyboard and mouse were plugged into and uninstalled / reinstalled all my mouse / keyboard drivers using Device Manager and it fixed it.

edit: also, dont take your computer to geeksquad / best buy. they will (try to) scam you (happened to me and my mom)

I've had the same hardware since I got this computer so I doubt that'd help.

Just to square on a few things- what power supply did you get?

What CPU and graphics card do you have?

Corsair CX500.

My GPU and CPU should be in the speccy I posted.

Okay, You mentioned the problem started when you switched to a new graphics card and it doesn't really sound like that has been completely explored.

Just because you see performance issues on the desktop does not mean something involving the change in graphics card (and it's drivers) is not the issue. I had a similar issue when I swapped cards and I traced it down to driver conflicts (and ATI catalyst control center) creating general windows performance problems. Video playback was laggy, and I'd get framerate hitches and other performance issues on the desktop.

Do you have ATI catalyst control center installed for your card? Have you looked at CPU utilization in task manager when you're experience performance issues?

Do you see anything taking CPU cycles when you're idle? The main culprit for me was catalyst control center which I believe is ccc.exe. You do not need the catalyst control center to use your graphics card, it can be uninstalled. In fact you should probably try uninstalling all your graphic drivers and if you have it catalyst control center, and then reboot. Then use the following program to clean up any graphic drivers still left over:
http://www.guru3d.com/content_page/guru3d_driver_sweeper.html

You could also have driver remnants from your previous card causing an issue, the driver sweeper program can remove those. Reboot again and do not manually install any driver. Windows will likely automatically install a driver- without manually installing any driver see if you still are experiencing the performance issues.

I've uninstalled CCC billions of times. The real problems started when I re-installed Windows 7 on my computer a week after I installed that hardware. I don't exactly think it's a graphics card issue

okay so you don't currently have ccc on your computer. Just to be sure there's no old drivers flying around you should try driversweeper, if you have not.

Since you already talked about wiping your hard drive I'm assuming you already did a full format and fresh windows install since experiencing the issue.

Any unusual CPU activity in task manager when you are 'idle'?

Sometimes Google Chrome takes some up but no, not at all. Memory is always around 50% taken, and disk sometimes jumps.

Just to rule another thing out Boot into Safe mode and Run driversweeper
http://www.guru3d.com/content_page/guru3d_driver_sweeper.html

It can clean up any issues with mouse/audio/video drivers.

I really don't think that'd help--I've been using the same drivers since day 1

Since we don't know exactly what was done on day 1 (when your problems began), and what has been installed from the get go it makes sense to eliminate driver conflicts as an issue. As unlikely as you may think it is, it's still important to do it and rule it out.

The key to troubleshooting is to eliminate the low hanging fruit and work your way up. Low hanging fruit is software issues. You've already been replacing multiple pieces of hardware with no result so I would think you'd be a little more willing to explore things that won't affect your pocket book.

I've been troubleshooting random shit with computers for 20 years and it never pays to leave a stone unturned.

Have you swapped in your previous graphics card at this point or do you no longer have it?

How is everyone overlooking the fact that dual channel memory only works properly with identical RAM sticks?

Also if you're running just 1 stick at a time you'll still have the same problems because you're running in single channel... which is a pretty big bottleneck nowadays.

It could be anything but not having (compatible) dual channel memory in your PC is a definite bottleneck and could well be the source of your problems.

That's what I was hoping people would get back to. What do you suggest I do?

single channel memory shouldn't be a 'big bottleneck', you wouldn't even notice it under normal circumstances and it shouldn't affect OS performance to any meaningful degree. You're looking at 1-2% impact on performance vs dual channel in specific applications, if that. Only noticeable through benchmarks.

If it's the memory that's the issue it's not because its single channel

I'm mostly looking at the off-kilter voltage and the CAS latency as possible problems here--I still haven't figured those out

Any crashes at all?

None that I'm aware of

bump

at this point, I would buy ram from a place with a good return policy and see if it fixes the issue, its most likely worth it to get 8gb of ram anyways.

Well, would I have to buy the exact same RAM that's in my computer right now?

How exactly did you test your RAM with memtest?

Try running Prime95 overnight.

No you can use any ram as long as it's compatible with your motherboard, so DDR3 up to 1600mhz and up to 16GB total.

I recommend getting a 4 or 8 GB kit (2x2gb /2x4gb) that runs at 1.5Volts, 1600mhz and are CL9, CL10 or CL11.

Kingston, Corsair and GSKill are regarded as the best RAM manufacturers so stick to those brands.

Here in the UK you can get a good 4GB kit at the spec I mentioned for around £40 or a good 8GB kit for around £60.

Before you go ahead and order some new RAM though I need to correct what I said earlier, single channel memory is not as big of a bottleneck as I thought. A single 4GB stick shouldn't bottleneck your current system and everything SHOULD work smoothly. You should be running in single channel with your hardware anyway as your memory sticks are not identical so could actually reduce performance if you try running them in dual channel!

I recommend taking the 2GB stick out your system and try and get the 4GB stick to run at the correct settings. You may have done this already and sorry if I'm repeating what someone has already said but try getting that 4GB stick working at the frequency, voltage and latencies the manufacturer recommends (this means changing stuff in the BIOS - if you can!)

Good luck.