For some reason, my game ran PERFECTLY on Wednesday, then crapped out on Thursday. I now get stuttering that I never had before. For starters, here are my specs:

Windows Vista Home Premium 64-bit SP2
AMD Phantom Phenom II X4 3.0 gHz
Dual ATI Radeon HD 4870's (Crossfire), each 1 GB of video ram
DirectX 11
8 GB RAM
Sound Blaster X-Fi Xtreme Audio

Sometimes when I load the title screen, it only gives me control of my mouse and keyboard after DLC's are loaded, but loads just fine other times (this issue never happened before Thursday). When i get the title screen errors, saved games and cell changes take a long time to load. I also get stuttering whenever I draw or switch weapons, and sometimes the radio skips as well. General movement in any direction also provides stuttering. These examples of stuttering occur regardless of whether or not I get the title screen glitch. I am aware that the ATI 10.10d drivers are supposed to fix some errors, but I'm running Vista and 10.10d is only available on Windows 7 for now. I'm not using that infamous .dll fix, either. Also, I'm not using any mods except the Caravan Pack.

Between Wednesday and Thursday, I did the following on my PC:
-Told Steam not to run on startup. Allowing it to load on startup has not fixed the problem.
-Ran Disk Cleanup
-Told Dell Support Center not to load on startup. Allowing it to load on startup has not fixed the problem.
-Switched internet connection from my Killer NIC to my onboard network adapter until I get the chance to upgrade my Killer NIC drivers. Did this in an attempt to fix another problem with my system.
-Temporarily switched to 8x AA from 4x AA in F:NV options once I read that the latest patch fixed stuttering issues. Changing these settings back has not helped.

Right now, I am re-validating my New Vegas files with Steam, in case a new patch was slipped in and caused validation issues.

Perhaps switching from NIC to onboard was what is causing these stuttering problems? I read that the problem with onboard networking is that it puts more stress on the CPU... I will look into this once steam is done validating my files (which is taking extremely long for some reason). Any other suggestions? Other than shelling out $120 of my limited funding (I'm one of the many unemployed US chemists) to upgrade to Windows 7?

edit: I know that a patch was released sometime this week that is causing issues for ATI users. I know that my game was performing VERY well during the time when the "essential enemies" bug in the patch was still present. Perhaps whatever fixed that bug could be causing problems for me?

edit edit: There is a chance I may have 10.10d installed, anyway, since I told Steam of upgrade my graphics card drivers fairly recently.

Hi Sniper4,
Dude! That's harsh eh? I'll bet you're ticked off...
Wow, I can only think that it has something to do with ATI and Crossfire profiles...?
Because the latest patch improved both my performance AND my appearance - without any settings changes!
I believe your ATI CCC has within it some answers for you...
I would make sure AA, AF and vsync are NOT forced from CCC.
CCC settings should be all high-performance or application-controlled.
And unless you can keep up 60 FPS (minimum) you must not enable vsync.
Your Crossfire profile I can't help you with - but you would think your performance would improve once ATI offered Crossfire support for New Vegas.
So is it now officially supported by ATI?
Also (sounds stupid) I found updating/patching completely fragged my drive - it was a 'sea of red' (Defraggler) whereas I had totally defragged everything carefully when I originally installed the game.
Might be a bunch of little things ganging up on you in your situation...
But, whatever - I hope you can remain calm, heheh
Regards

Thanks for the reply . I checked my CCC settings and everything looks fine. I re-verified my game with Steam, then attempted to play. The game was still stuttering at first, but was better than before. I no longer got stuttering when changing or drawing weapons. It also seems that the longer I play, the better the performance I get. I'm starting to wonder if the Disk Cleanup utility deleted some sort of cache that the game was drawing from to improve performance? What makes me think about this option is that I notice that I get great performance in places that I've already visited after the cleaning and choppy performance in places that I have yet to visit. Perhaps the next patch for the game or next ATI driver update will fix my problems as well, since it seems that a small hand full of ATI users are having similar issues after the patch.

I'll just have to keep playing and see how performance fares, yes? I'll also consider scheduling a defrag soon, since I'm not sure that the scheduled Wednesday defrags are accomplishing everything they should. Thanks again for the reply .

Ahh, geez. What's up with that?
But they did mention 'nVidia performance' specifically in the last patch, didn't they...
I have an MSI HD4870 1GB here somewhere, great vidcard.
Pretty well just as strong as my new GTX460 I'm running - and DirectX11 is no big deal.
Great vidcard - but the ATI software was driving me crazy. I was in CCC hell...
So I jumped ship.
Trust me, things are just so much better in nVidia-land...
The drivers are much friendlier and easier to keep up to date.
Anyway, looks like problems are just temporary for you guys, so...
Ack - television!? Lord no.
Seems like they're taking forever with the updates, heheh
L8R

The 10.10d:s don't fix anything, at least not for me. The patch halved my fps and updating my drivers didn't help at all.

This is an update on the situation, in case it helps anyone.

Problem solved! It turns out that two Dell services, "Advanced Networking Service" and "Remote Access File Sync Service" were both constantly accessing my hard drive, causing *everything* to be much slower. Disabling these services drastically reduced the "traffic" going in and out of my hard drive, allowing everything in my PC to load normally. I haven't had problems with these services before, so something must have triggered their misbehavior.

Anyway, between that fix and the uber defrag I did, I'm getting the best performance I've ever had on this rig, and it's over a year old. Thank you all for your support .

edit: More good news: my mom says that after we get the inheritance from my Grandfather's estate, she'll give me some money to upgrade to Windows 7 . Ironically, I get this news after getting Vista to work better than ever .