Game slowdowns

[Cpt.Maximum]

At first I thought it was my graphics card (which, admittedly isn't stellar), but all the games I have ran just fine before. As of a couple days ago, each of my games run fine until maybe 10 or so min in, then they start lagging badly. Notably with Deus Ex, TF2, and DoW Dark Crusade. Like I said, they had been running just fine beforehand, but it wasn't until recently they decided to lag on me.
My specs:
Windows 76 64bit
Nvidia GeForce 9100 graphics card
6GB of RAM
AMD Athlon(tm) II X4 620 Processor

I just did a Defrag of my computer, I make sure I don't have unnecessary processes running, I verified files of some of my games, and defragged those. I updated my video cards drivers just to be sure, and I made sure my computer was up to date.

Like I said earlier, my graphics card isn't great, but its been able to play games just fine earlier.

Also also, this computer is new. Not even a month old.

Can anyone give me some help? It would be greatly appreciated.

[HL2-4-Life]

Normally, if a game starts to lag after a few minutes of gaming, it's a sign of GPU overheating.....may possibly be CPU overheating as well, so it throttles down to cool down. In all honesty, I don't get that you can play those games with that system, or more specifically, that 9100.....it's really not meant for gaming actually.

[Cpt.Maximum]

I had doubts I would as well. But it was running TF2 just fine on rather high settings. Company of Heroes I had to tone down in graphics to minimal, but it ran fine. Though, even if it isn't a good card, I don't see why it wouldn't play 9 year old Deus Ex without lag.

[Fatimmortal]

Isn't 9100 an integrated card?

Since it is, it probably wasn't made for gaming.

As far as I know, integrated GPUs don't have any fans for cooling AT ALL. It's a miracle that you can even run TF2 on higher settings.

My guess is that after all the stress you put on it over time, it kinda starts getting fried.

I've also noticed that OP isn't the only one with this problem as there are many other people with the same graphics chipset that are experiencing the slowdowns.

[Cpt.Maximum]

Yeah, its integrated. If this is the case, then I'll see about a better graphics card. I probably did push it over the edge. Thank for the help, guys.