Just wanted to know if I'm the only one who's seen this, after applying the HD pack i was getting wicked bad stattuering, checked me VRAM and it was spiked at over 1900MB used, my usable vram is actually only 1024MB so obviously this was no good, after disabling crossfire at the suggestion of someone o these boards the vram dropped back to 976 used, whihc is a bit higher than it was before the pack, and more in line with what I expected.

has anyone else encountered anything like this in a multi-gpu environment?

I'm going to upgrade to the preview drivers after work and see if that has any effect.

Depending on which tool you used, quoted VRAM usage might be double the real number.

Not likely the case, I did a simple test. stood outside markarth next to the windmill and span around in circles. With crossfire enabled in started chunking out and dropped the FPS in to the single digits, with crossfire disabled it was still quite smooth, even spinning as fast as I could get the mouse to go.

And previously when I had used the tool to report the vram usage before I added the HD pack but with CF enabled it was running just fine at about 954MB used.

I have two 6950's in Crossfire and I have run into some programs that miscalculate the actual vram usage. In fact, there is a known issue with MSI's Afterburner not returning the proper vram usage with AMD Crossfire setups.
IE, the new beta they have out.

Anyhow, I highly doubt you are actually using more vram than what you have effectively. The likelyhood is faulty software. You should try GPU-Z, it was reporting the proper amount for me.

I ran into the same problem you are with my two GTX 460's when I tried to run HD textures. The single GPU did not stutter as much when it was hitting it's vram limit; however, whenever I enabled SLI, the two cards stuttered like crazy. I'm no graphics card engineer, but I believe this has something to do with the strain and having to sync both GPUS. The fix was going with the 6950 2gb vram crossfire setup... i've had no issues with stuttering since then.

You can test this theory by throttling back AA which is a major vram abuser... If it doesn't stutter then i'm pretty sure it's what we think it is.

As a side note, there are a lot of folks running into vram limits lately huh? Makes me feel better about my choice to drop NVidia and their skimpy vram cards.

I am using gpu-z.

I am trying to use my two 6570s in crossfire. I keep getting flickering in an area from the top left across to the bottom right.

I have the 12.2 drivers and have tried each selection of crossfire modes. All the other settings are for application settings.

I had the HD pack installed but saw this and took them off. Keeps flickering.

Any ideas?

System Internals (Free) from microsoft comes with a program called Process Explorer. (google that) It will show you that YES you can indeed go over the Actual Vram your card has. I have been 300 MB over the 1024 my card has. Todays modern Video cards will ask the System for its Ram. This will cause you to have sever stutters and can cause you to go from 50-60 FPS to 5-10 FPS.

Dont trust what i tell you , download "Process Explorer" it will show you what none of the other utilities will . It can actualy Replace "Task Manager". The following is a screen shot of Skyrim running for 19 hours. the shot after is showing that my system was using 250 meg of System RAM.

http://i232.photobucket.com/albums/ee72/camaro_69_327/Skyrim/Skyrim19_hours32Mins.png In the top header of that screen you see the name of the program and the Address to get it.
http://i232.photobucket.com/albums/ee72/camaro_69_327/Skyrim/TESV_2012_01_01_11_38_01_055.jpg Looking at the bottom graph is System mem at 250 MB I was getting stutters , it takes 3 hours to fill that graph all the way across like that .. Now even tho the Vram was not filled to the top, it starts using system ram when the card sees that what is being asked for would saturate the Card. So instead of using the last of the available Vram it just uses your system ram. I used this to tune my Game to use only 900 MB so it never goes into using System RAM.

You will not see this using Gpuz or MSI or what ever else you want to try. Least i never found one showing me what my GPU was really using. This does ..as you can see. The top Graph is the GPU (engine) usage. the Middle graph is the VRAM (GPU) bottom is RAM (System).

You can get Process explorer on its own or get the Suite. It plays very nice with Skyrim as you see i ran them together for 19 hours straight! Your mileage will vary.

Till you see what your System is giving your GPU you can be Overfilling it and never know! I didn't.