[Solved] Quick Core 2 Duo T8100 CPU has 100% spikes on old game

Whenever I play the game GTA Vice City, the game runs flawlessly at high resolution for a while, but then has intermittent, long and frustrating periods of extreme lag -- seriously my fast car doesn't slow but completely stops. Tabbing out I see my CPU at 100%. But if I open the task manager and sort by CPU, no process uses near that high recourses -- most at zero, some occasionally go above single digits, taksmgr is greatest % for a bit, the gta-vc.exe process never goes over 20%. I've tried lowering resolution, but lag happens just as often.

This is an old game and my quick PC should easily be able to handle it. Seriously, the system requirements for this game are pathetic. I installed on 2 other computers, both are significantly less powerful (one has a 2.4Ghz Celeron processor) and still handle the game well, never lagging.

What could be the cause?

Thanks in advance

Might be running out of RAM, and using the HD (which would be slow, and not typically caught by task manager). Given how GTA games load so much of the environment at a time, its possible.

OK, I got some more detailed process data. Looks like the CPU starts around 50-60 avg, hovers around there for a while (yet always with slight up & down variance) then slowly increases till it hits 100%, which is when the game starts to lag terribly (movement completely stops - freezes). I tab out and wait and eventually when the CPU gets low again I tab back and continue playing. Memory never gets much above half (I have 3 gigs).

I tried playing the game and monitoring recourses on the Celeron desktop for comparison. It's CPU usage is a constant 100%, except for an occasional slight downward tick to about 95, which is only momentary. I've noticed on that system, the game occasionally stops and shows a "loading..." screen for a couple seconds (this may be the cause for the downward CPU ticks). The desktop never lags, and plays the game great.

I think my problem on my laptop may have to do with the game never doing the loading screen. I figure at that time the system takes a second to breathe, gets its stuff together, then proceeds gameplay. Maybe it has to do with the game figuring it shouldn't bother w/ the load screen because of my system's hardware? Or could it possibly have to do with my laptop running Vista, as opposed to the desktop's XP?

It doesn't seem to be a process outside of the game, as the game lags once that process spikes to full CPU. Arg, how can I get this game to run properly?

Hey guys, author of the question here, I finally seem to have solved the problem. Gamerk316, you had the most accurate post (although unfortunately I can't modify the "best answer". Basically, the laptop was overheating, lagging the game, then eventually getting my gaming frames back. I use the laptop on a desk, so the "feet" rubber pads to lift it slightly, however the air underneath still seemed very hot. I was thinking it'd probably help if I could get the laptop lifted higher in some easy way, and found a quick solution. I grabbed four watter bottle caps, turned 'em upside down, and put 'em at the four corners. The feet fit inside so they stay put, and since they're all identical height there's no rocking or anything. I was getting crippling game stopping lock-up style lag playing Vice City, then I put the caps down and I haven't had it lag since at highest resolution. I guess the lesson is, laptops can overheat EZ, and water bottle caps can come in handy.