I still have this No Input issue several months after release. At random points playing Skyrim, my monitor goes black and a No Input message pops up, the sound cuts out 20 seconds later. It doesn't happen with any other game and I can run games like Battlefield 3 and such on max.

Someone recommended underclocking my GPU because it worked for them. My question is, why would I need to underclock a GPU that is better than the recommended system requirements for Skyrim? And how much would underclocking reduce performance?

One of the reasons underclocking a GPU could or would work is IF your PSU is starting to fail this would lessen the load and allow you to play.

IF underclocking does help I would then look for the cause...either bad GPU and or failing PSU.

All Power supplys slowly lose there rated watts over time. this is a givin...

I experienced the "black screen" crashes in Oblivion. everyone told me it was my PS , I argued. I also said...but I can play such and such for hours....I was wrong.

My dumb ass had to learn the hard way.....I said..na its got to be the GPU...Bought a NEW GPU and guess what ...black screen crash with new gpu...sigh..bought a new PS and BOTH cards then worked...

YMMV

I bought a brand new 850W PSU just for this problem.

But I don't think it's hardware because like I said, other very demanding games run fine.

Could you post specs? Also post specs on your psu. You only need to underclock if you have overheating issues.

Radeon HD 6870
Windows 7
i5 2500k CPU @ 3.3GHz (4 CPUs)
8GB RAM
http://www.newegg.com/Product/Product.aspx?Item=N82E16817153106

I have checked the temp in BIOS immediately after those hard resets and the temperature was normal. It's normal while playing the game too.

That's odd, however you can't count on bios temps if you restart your pc. It only takes seconds for the temp to drop if you have a proper heatsink.
Specs are good, other games work. I really have no idea at this point what might cause it. I must be a software issue, not hardware.

Do you have mods installed?

Yes but it happened in vanilla as well.

Hmm do you have any GPU temp monitoring app installed at all? If not, grab Afterburner http://event.msi.com/vga/afterburner/download.htm
When (or if) it crash, exit the game and check temps.

I find it very odd that you can play other games without any issues.

It doesn't give me a chance to check the temps. Mid-game it shuts the monitor off and I am forced to hard reset.

Ok do you hear the gpu fan spin more when playin skyrim compared to other games?

Not noticeably louder.

....MSI Afterburner will log to a file in the background....on the monitor page click to have the program log to a file.

Then play till you crash....note the time of the crash...after restart open the log and check for any oddities....

I did that and the highest temp was 69 degrees. Last I checked that isn't terribly odd.

Card has a barrel fan he would hear it anywhere even close to 100% trust me on that lol....my card has the same fan and it sounds like a jet engine. Unless you have an MSI Twin Frozr OP in which I doubt that the factory OC on that would cause the issue. Are we talking an OC'd card from the factory or you OC'd it yourself? Or is it stock speed and I am derping? Also MSI has monitored my game with GPU temps in the 90's and it chugs along fine on my 750w Corsair which is 80 Gold but that PSU the OP linked isn't terrible and def plenty for his card etc.

What could quite possibly be happening is this....ATI makes card BIOS to run quiet over cool and thus for instance my card just sits at 25% speed and once it gets to about 90 C it hits 40% but this doesn't do the trick and the card runs very hot....quite possible over time too hot. I use the MSI program linked above and a custom fan profile to keep my GPU at 80 c max during gaming and the fan runs much faster than it would stock and thus cooler.

So.........your card using just basic CCC could be overheating if it has some dust and wear etc. I highly recommend having the fan(if it is a single barrel fan) running between 45% to 55% speed while gaming. You can do this manually with Overdrive in CCC(catalyst) before gaming or set a profile in MSI that monitors it better than the card BIOS will alone with the ATI drivers and software.

I haven't touched the overclocking yet. Would I be speeding it up or slowing it down? Like I said, it reaches 70 degrees playing Skyrim, no more.

What brand card is it? XFX, MSI, ASUS, etc.
Looking at your specs I mean we have the same PC basically I may have more RAM but big whoop 8 or 16 shouldn't matter it's plenty. I also have a little more VRAM but my card is far from fully supported still so its like the same thing with more room for textures. Just curious what kind of display are you using as well? What OS? is it 64 bit? Any programs running in the background(aside Steam although I recommend playing with Overlay and Comms off).

Might sound silly, but have you tried backing up anything important, formatting your hard drives and reinstalling windows? When I can't solve a problem that is important for me to fix, that is one of the first things I do, generally good to do every do often anyways to keep everything running clean, and it eliminates 99% of absurd conflicts or small errors that can cause a crash like that.

That is if you have truly exhausted all obvious problem sources, especially any form of overheating. Is the computer in a cramped space at all that could heat up?

My graphics card is Radeon HD 6870 and I use Win7 64 bit. Nothing big running in the background sans Steam.
I haven't tried that yet because it only happens with Skyrim.

I would if I was you if you can't get it working, there could be some small file or program that is barely noticeable and causes a conflict, but only with skyrim. You seem to have gone through the normal troubleshooting is why I suggest it.

I ran something a while back microsoft performance fixit I think it was called basically ensures clean boot and cuts startup stuff out of the process. Of course these programs will still work they just won't load in the background when windows boots up. Here it: http://support.microsoft.com/mats/slow_windows_performance/en-us

Also for the record if I play BF3 the ESN Sonar can cause conflicts with Skyrim so I always restart before a game of Skyrim.

I've tried running it immediately after a hard reset where the only things that open automatically are Steam and Dropbox, the latter I close immediately.

You have Steam booting with Win? Have you tried setting it to not do that and see if you get any change?

Yeah, no dice. This is hopeless.

So this just happened again with the Sniper Elite V2 demo, which isn't very graphically demanding. Could it still be my card?

1. Did you update your drivers to the latest?

2. Did you pay attention to your temperatures?

3. Did you look in Event Viewer for errors?