Hyperthreading - How much difference does it make?

[RobertJ 10]

I have hyperthreading enable at the moment and I'm seeing some (gamebreaking) issues in Operation Arrowhead, textures trash, fps drops randomly and the game just plays A LOT worse than ARMA 2 did on lower settings. Not only that but the ARMA 2 maps like Utes play awful compared to how they used to.

Just a couple of pointers before people answer

-> Yes I've tried -winxp

-> Catalyst drivers 10.8

-> Graphics card temps fine (Checked)

-> CPU's set to 4 makes no difference

-> exthreads at default (whatever that value is, 7?)

-> maxmem tried to no effect

ARMA 2 worked fine with hyperthreading, and disabling it can be a bit of a pain.

images

-> Horrible LOD, tree is just a blob, ground is 2d (this is a good level of trashing for me, at worst the textures just totally go)

http://img84.imageshack.us/f/arma2oa2010083119232792.png/

-> Ground, Vegetation and Unit model are all trashed up

http://img529.imageshack.us/f/arma2oa2010083119272079.png/

-> bad ground

http://img230.imageshack.us/f/arma2oa2010083119325907.png/

[xman1 10]

Never heard it kill textures. The only thing it should do it kill FPS. I've watched the CPU on ARMA 2, and it hardly makes use of a 4th core, so if you already have a quad, no use in adding additional fake CPU's via hyperthreading.

Hyperthreading is based on the idea of CMT. It doesn't really give you another CPU. It just allows a CPU to do two tasks while avoiding the time taken for task switching as found in SMP. It does this by splitting the workload or MHz between the tasks. The downside is that SMP will run a single thread faster because it always runs the thread at maximum speed. CMT will run multiple threads faster. If you app is only running 4 threads, then no use using CMT when you already have a quad CPU.

-X

Edited September 14, 2010 by xman1

[Rich_R 1087]

I'm no expert but dont think it has anything to with Hyperthreading.

Had exactly the same problem (just like your attached pic) which came about after the last Arma Patch, but it wasn't BI but the catalyst drivers.

I rolled back my drivers to 10.4 and not only did the textures and LOD fix themselves but the game ran noticably faster and smoother. Since I did that however, ATI issued an updated to the 10.8 drivers (b maybe) but I didnt want to mess with the performance I've been enjoying with the 10.4's.

As for hyperthreading, I just read an forum post where a gamer tested the same games with hyperthreading on and then off. There was hardly any difference. The exception to this would be (supposedly) if you over clock. By taking the hyperthreading off, the CPU runs cooler and allows more room for hyperthreading.

[kklownboy 43]

HT can be very problematic with Multi-GPU setups. Yes they can have a effect on all things rendered, but the most common is just plain lag/stutter. CF and SLI are both effected by HT issues, Its a Driver issue on some Drivers. Your milage may very.

IMO, where the driver wants to off load/balance ect ,to the "extra" cores but the Game engine wants it different. This can crash(early SLI A2 issue) or lagg/stutter( early CF A2 issue). Its all about finding the right driver to the version/Patch of the Game. But the easiest way is to just turn it off, unless you really have a multi-core App that uses eight+ "Cores".( highly doubtful). there are a few of you on this form who edit video sooo.. it may help, and the 3Dmax guys ect... But for regular Game play its a not needed.

[=wfl= sgt bilko 10]

For the OP the main issue with HT is basically bad and fluctuating FPS. Hard to tell if your issues are HT related.

My personal take on hyperthreading and games in general is that you're better off with HT disabled. It was a big problem back when the Intel P4 CPUs were the standard and I don't think that has changed. I see little point in having it enabled at all with current batch of mulitcore CPUs.

For a gaming computer, there are two things I always recommend:

- Disable HT in BIOS.

- On NVidia gfx cards, set GPU accerleration to "Single Display Performance Mode" (even if you only have one display) in driver.

Addendum: Actually three things. Just got reminded after reading theslow disk speed thread:

- Install proper chipset drivers and check that your HDDs controllers are running in DMA mode.

Edited September 15, 2010 by =WFL= Sgt Bilko

[Alex72 1]

For me HT destroys FPS a lot. The cure is to use the startup command -CpuCount=4 (goes into the TARGET field of the ARMA2 shortcut) which works the same way as disabling it in BIOS, and i rather have it disabled for ARMA only instead of completely for all programs.

I notice of course that OP ran ARMA fine with HT, but just mention the startup command so others wont need to go disabling it in BIOS just to play ARMA if they have the same FPS stutter as most with HT on. ;)

[RobertJ 10]

Well I just installed Catalsyt Control Centre 10.4 to no effect, the LOD trashing is still there.

Any ideas at all? Do I RMA my card, send it for repairs. It's really hindering play when the entire game goes to lowest LOD and looks worse the OFP =(

[NevilleBartos 10]

maybe your HDD needs a clean out? try a defrag?

I have an i7-920@ 3.8GHz, HT disabled or enabled makes no difference to me, i have it disabled anyway because i dont use HT.

Edited September 16, 2010 by NevilleBartos

[RobertJ 10]

Total removal of all display drivers then a reinstall of Catalyst 10.4 sorted the problem. ARMA 2 OA has to be renamed to ARMA2.exe for Crossfire to work but it fixes the LOD problems.

[Richey79 10]

I agree about Catalyst; I'm still using 10.4 myself (with 10.8 XFire profiles) after trying the later builds.

[Nephris1 10]

to use the startup command -CpuCount=4

Isnt it already by default since a patch ... i think 1.50 or 1.05.

It was introduced by a beta patch and i guess it was b4 OA.

So a real clarification, maybe by a dev, or s.o. who has really a clue about it can make a statement about it.

My ArmA2 is running great (i7 920), so i never really thought about disabling HT, even less since cpucount was introduced.

Neverthelss a liable statement would be cool, otherwise this myth will reach the Mythbusters anytime....:p

[polar bear 10]

Whether HT helps or hurts you seems to depend on many factors. I don't know so well with ArmA, but I know with Valve Source engine games that depending on your rig and config in those games turning on HT can create a lot of stutter. ArmA's obviously on a different engine and implements multi-threading quite differently so YMMV.

The reliable reason to turn it off for me is that ArmA does not seem to use more than 3 cores (by observing CPU usage) and so with 4 physical cores there is really no good reason to turn it on and simulate having 8. It can't help, and it might hurt.

Of course it might make no difference at all and in that case if ArmA is not the only thing you do with your rig, if you play other games, and HT makes no difference in ArmA for you, it may be a benefit in some other app or game.

No way to say for sure what it will do on your rig so I'd basically say just play with it on for a few days, then play with it off for a few days, and see if you notice any difference either in FPS or in stutter.

Edited September 16, 2010 by Polar Bear