continuation from a now-not-so-hi-jacked thread


First off, I'm not an expert - I've done a lot of reading on this subject, but I'll admit that I'm still bit fuzzy about HTT/multi-threading. I know the basics, but...

Anyway, what I'm about to say may be completely wrong, but this is my current understanding of it:
I'm going to refer to Hyper Threading as HTT (Hyper Threading Technology).

HTT is a form of multi-threading. HTT being a trademark name used by Intel primarily for the P4 processor family with two logical processors. But I often see it get misused as a catch-all term for any system with multi-threading capability. It is my understanding that a true multi-threaded CPU is one having more than one PHYSICAL core - whereas, HTT refers to having only one physical core and two logical processors. An HTT-enabled CPU is not nearly as efficient at dealing with multi-threading as a multi-core/multi-threaded CPU. I also believe it's easier to implement multi-threading in a multi-core system than it is in an HTT system.

Goldsource/Source gaming
I know for a fact that Gldsrce is NOT HTT/multi-threading compatible and never will be (what's the point?). But I thought I read somewhere that Valve had made the Source engine multi-thread compatible in one of their many updates (but not necessarily HTT compatible). Maybe it was only applied to certain titles at first (TF2, EP2?)? I don't know, maybe something else is going on with my system, but this seems to be the only explanation as to why my CPU usage is almost even when running EP1. I'll try other Source titles later.

Looking at the Steam hardware survey, I remember it used to show HTT percentage - I think it was only about 10% at the time; whereas in their current survey (Mar '09), users with more than one physical processor (not HTT) is at 71.27% - that's pretty significant.

tl;dr
Anyway, I'm just trying to make sense of my task manager readings:
(I added color-coded bars to illustrate what was happening at the time)


EDIT: Oops, forgot to label the separate Logical Processors...


As for my FPS in SC: I'm usually at my 75 fps cap at low demand, somewhere around 50-60 during normal gameplay and it drops to about 30-40 during intense scenes (I've seen it go as low as 5-10 sometimes ). With Fraps, it will usually shave about 20-30 fps off anytime it's recording. Best I've seen with Fraps running is about 30 fps.

Only the orange box engine supports multithreading, and you have to set it up manually with commands to use more then one core, and is unstable if you try to use more then 3 cores on it. With HTT processors you have 2 logical cores but the cpu wouldn't be as fast as a real dual core cpu. For instance if you were to run a process that uses a lot of cpu on one logical core that process would become slower if you were to run one like that on the other logical core, on a dual core the one should run at close to the same speed as before if you were to run one on the other core(as long as it's something not extremely ram intensive.). As for the last image, if your doing a lot of swaping or even texture thrashing(having the graphics card referance textures in ram or swap, causes a very low fps.) in game that could raise up the second logical core cpu usage a bit.

Most recording programs cap your fps at the recording speed, so if you set it to 30, your game will be capped at 30fps when recording.

As for fps, I get on average around 80-100 on most maps, not in a fight seen, and down to 30-45 on maps in fight seens, maybe a little lower on the complex maps. If I turn dev mode on(which allows you to have an fps higher then 100.) I've seen fps's upto 150-250fps on some of the simpler maps.

I know this thread is pretty old but wanted to chime in with a note.

In windows XP and above, with more than one logical/physical processor, you can actually tell a given process to run on a given core. See the attached jpeg - in the task manager, right-click on a process and go to 'set affinity'.

If you're seeing a single core being stressed by half life, you should be able to tell FRAPS to only use the other core. theoretically that should help.

Yeah I know about the set affinity thing in the task manager, but not all programs obey it though, hlds doesn't unless you use a special flag on it when you start it up, something they added in the update they had late last year, not sure about fraps though, most programs should obey affinity setting though. I wonder how xp and vista shifts processes around from core to core, if it was on Linux is should automatically use the other core if a program is using most of the other, wouldn't really know since none of my comps have a daul core cpu in them.

You may have to set affinity on the game to to get good record speeds in fraps/xfire, you can set hl to use core one and the steam client and xfire/fraps to the second core.

Both xp and vista are SMP capable oses , if you had win 2k, you wouldn't be able to use the second core on a dual core cpu.

lol, there's quite a few processes running in that screen shot, have 55 running on mine(1.2gb of mem usage though...)