I did try putting iNumHWThreads=8 in ini file. Then I used http://www.techpowerup.com/forums/showthread.php?p=1732756 to see if Skyrim can use all 8 logical cores.

It turned out Skyrim can only use 2 logical cores. (http://i.imgur.com/jfxTQ.png)

So, if anyone wonder why their high-end multi-core CPU does not run Skyrim well, now you have your answer.

note: I ran Process Monitor while running around Markarth (where I have the most FPS drop) for ~8 mins.

Well, we did know about the issue of Skyrim only utilizing 2 cores no matter what chip, but thanks for sharing. It is good to see more accounts of this issue

Those tweaks never work, its built right into the coding of the engine, so you cant change it in the INI file without rewriting the engine to allow it.

I assume it was the same with Oblivion?

The recommended spec is quite misleading, in my opinion.
By recommending "Quad-core Intel or AMD CPU", does suggest that the game can utilize 4 cores.

The game can put some minor work on a lot of cores so there's clearly some threading going on. As long as it's so badly bottlenecked by whatever's going on in the 2 main threads the extra threading hardly seems useful at all, though.

The "quad-core" was probably just meant to imply a high-performance CPU for PC hardware illiterates with bloatware hogging CPU time in the background (and any one of them with a low-spec AMD quad is pretty screwed).

I get about ~40-50% CPU usage on all four cores peaking at ~70%, I hope you checked while running the game in windowed mode? If not usage will drop if you alt+tab out...Sadly I cannot remap the take screenshot key of Skyrim so I needed to tab out of the window as well...:
[IMG]http://i.imgur.com/0HzlF.jpg[/IMG]

I just tested this and mine used 3 out of 4 cores but I'm not just using INumHWThreads. It could be either because I am using Skyrim Enhanced Shaders (an enb mod) and FXAA or because I have other additions to my ini files for threading.

PS. I didn't try in windowed mode and just checked after quitting the game.

I ran the game in fullscreen, the usage drop at the end happened when I existed the game.
However, that is not relevant because a drop for a second or two would not affect the average CPU usage data in a meaningful way.
What I really interested in is the maximum number of logical cores Skyrim could use. For a high-profile game of 2011, I hoped to see at least "4/8".

I just mentioned the alt+tab thing because some folks are not aware of this There is alot of threading options for Skyrim in the INI's and I think most guides do not yet really utilize those. Make a backup of your current Skyrim.ini then when Skyrim is running open the console and type:
saveini

Open the Skyrim.ini (now a ~41kb file) in My Games/Skyrim and start searching for "thread"
What I find in it after doing so:

I have these set in skyrimprefs.ini

under [General]
bUseThreadedParticleSystem=1
bUseThreadedBlood=1
bUseThreadedMorpher=1
bUseThreadedTempEffects=1
bUseThreadedParticleSystem=1
bUseThreadedTextures=1
bUseThreadedMeshes=1
bUseThreadedLOD=1
bUseThreadedAI=1

under [Navmesh]
bUseThreadedMeshes=1

under [trees]
bUseMultiThreadedTrees=1

under [Decals]
bDecalMultithreaded=1

and these in skyrim.ini

under [General]
iNumHWThreads=4
iRenderingThread2HWThread=1
iRenderingThread1HWThread=0
iHWThread6=5
iHWThread5=5
iHWThread4=5
iHWThread3=4
iHWThread2=4
iHWThread1=4
bMultiThreadMovement=1
iAIThread2HWThread=5
iAIThread1HWThread=3
bUseThreadedMorpher=1
bUseThreadedParticleSystem=1
bUseThreadedTempEffects=1

under [Audio]
uiAudioHWThread=2

under [Havok]
iNumThreads=4

under [Backgroundload]
bUseMultiThreadedFaceGen=1
bUseMultiThreadedTrees=1

Besides other additions and tweaks.

I did tried all of those options you posted. The game still uses only 2 cores. (http://i.imgur.com/1YIGI.png)

Edit: For comparison, http://i.imgur.com/hzde1.png is what an efficient software would do. A good software will use all available processing power to finish the jobs as fast as it could, in this case, Foobar2000 was anolyzing ReplayGain.

Alright I checked again with the tool you had used and it seems like Skyrim is using 3 of 4 cores on my machine but taskmanager/ressource monitor reports usage on all 4 cores:
http://i.imgur.com/1tx5c.jpg

I don't think it does either, although apparently the havok threads thing does because it is a premade package or something. /shrug

I run a 2nd monitor and have all my usage monitoring stuff running, and for the vast majority of the time my CPU soesn't exceed 53%, but it has spiked to about 60-65% during gameplay. Of course, that could have been from a background process so who knows.

At least my gpus are getting good usage.

Edit: I'm going to try these other ini options later. Here's hoping.

Task Manager always does that, even with a software I know for the fact that it only uses single core. The graph however will show like the software use a little bit of every core.

Same here, Task Manager and Resource Monitor shows 4 cores being used, i seen them go as far as 50 to 60% CPU load.


Running on a CPU AMD PhenomII x4 810 (OC to 3100Mhz) with 6Gb of Ram with a HD5770 1Gb GPU, i play on Ultra Detail on 1280x1024 with no issues of crashes but many many hilarious glitches, also using 1.1 patch and my max frames i seen is 78 exteriors and my lowest was 17 on Markarth, i used a FPS limiter and my frames dropped to 30 EVERYWHERE, even in crowded cities, heck even in markarth i get constant 30 fps... its worth if you dont mind being capped to only 30 fps everywhere.

So far i can play the game as smooth as butter, i dont really have nothing to complain... well i do, the damn key binding is bugged, i need to use the xbox360 controller just to assing a favorite item/power then go back to keyboard to bind the favorite to a number.