e6540 with 8790M : hardware defect or worthless laptop for gaming ?

Hello,

I recently bought a Dell Latitude e6540 with an intel haswell 4800M and ATI 8790M. I'm very happy with the laptop, except for gaming.

When I play a game (let's say BioSock Infinite in medium-high at 1600x900) this happens :

At first, around 70FPS, CPU is at 3.5GHz, all works perfectly
10 minutes later CPU is at 0.8GHz, but the game still works somewhat (30-40 fps with noticeable lag spikes)
5 minutes later, CPU is still at 0.8GHz, but the game dropped at 1-5 FPS, and the computer is unusable (like waiting 2 minutes for a key press). The CPU is around 70-80 degree celcius

Only thing to do is shut down the game and wait 5-10 minutes for the computer to become usable again. I tried Bioshock with lower resolution, lower settings, it takes a bit longer but the same problem appears. This happened also with FarCry3, Tera Online... it even happened once in League of Legends (a game who should run on high on a computer 4 times slower).

I have all drivers up to date, bios included.
I can't see a Dell technician right now, but people have been telling me it's just normal cpu throttling... I've tried disabling cpu throttling in the bios : my CPU now doesn't drop under 2.7Ghz, however the exact same things still happen. After 15 min the computer is unusable.

I hope someone has some experience with laptop cpu throttling to tell me if this is normal. Yes, this is a business laptop, but I don't see why they would put a 8790M on it if you can only use it for 10 minutes a time.

 

temps, how are they? it looks like its throttling due to temps

 

Idle : 50 degree celcius
While gaming : it goes up to 90c, then down to 75-85 when CPU starts to throttle. Which isn't a problem in itself, I understand I can't keep 3.5ghz for long, however 0.8ghz seems way too low for 75 degree celcius, since it's a temperature I achieve quite easily without even gaming.

Also as I said, I even tried to disable CPU throttling (just temporaly in order to test) and the computer slowed down anyway (altought the cpu frequency stayed at 2.7ghz). Without CPU throttling I expect the computer to maybe shutdown if too hot, but not slow down... But maybe I'm wrong about that.

 

if you're game, you could try a repaste, and reseat the heat sink

 

The laptop is two weeks old so I'll let a dell technician do it. Right now I'm moving so it'll have to wait, but once I'm done I'll definitely ask for a technician, probably parts replacement ... What I fear is if everything is okay and that's just the way the e6540 is. Maybe I will have to wait a long time for a new e6540 version with better cooling, like what seems to have happened to the XPS15. Or maybe this wil be a life lesson about no buying a laptop recently released...

 

Definitely either needs a repaste or faulty parts. Hope it's the former for your sake.

 

I've experienced the same. An review elsewhere also highlighted this issue.

I believe it's an inherent flaw in the system, much like Dell's XPS15.

 

I have an Samsung ultrabook with the mentioned GPU and no throttling neither at CPU nor GPU side;

​

Check your computer with the same programs while you play games, Aida64 will show how badly CPU throttling occurs and temperature, while MSI afterburner will tell many information about the GPU. Maybe for you both CPU and GPU are throttling due to high temperatures.

 

I'm now finding this system basically won't function at the full 2.7Ghz. I have to use SpeedStep and run the CPU underclocked at 2.3Ghz to prevent overheating and throttling with games.

 

your point? we all know its throttling. if you aren't going to do something about it, the only half backed option is to throttle yourself?

 

Don't be obnoxious eh.

The point is, that surely a system should be able to function at advertised speeds. I paid for a CPU designed to run at 2.7Ghz, not. 2.3. Dell have seemingly set up the laptop to run at a ceiling of 2.3 by default.

 

my point is, you have enterprise class service, use it and make dell fix it. from the xps line there is little hope