Will a M17x R2 i7 820QM handle a 7970m

Hi

Im new around and certainly a beginner in this matters, I have an alienware M17x R2 which has 4870m x2 and I wanted to get a 7970m single.

I was about to buy the card when I read that my CPU i7 820qm could be too slow and bottleneck the 7970, is this true? my intentions are to run games at high settings, the recent ones ie MW3.

My best concern is whether investing in adding a 7970m will be worth, my intention was to later add a second card in crossfire, I mean later when the 7970m single starts to show age.

I dont want to throw thoundsands of dollars into this system if I will not get a system that would last for at least 2 or 3 more years playing recent games, I was thinking on selling and investing 1500 dollars in a desktop so I would invest in something better for the near future.

So, questions are:

Is the 820qm enough to handle the 7970m single? If I crossfire someday, will I need the 920xm or 940xm for sure? (I know a psu mod will be needed).

The thing is I have the money, but I dont want to invest it in something that would not work at full potential because of limited CPU capabilities and would rather sell the system and configure a nice desktop.

 

A 920XM would suffice but you are correct, a psu mod would be needed once you had two of the 7970m's however with just one you should be fine with your default supply. The problem you will face is that the 7970m will infact be faster then your current crossfire card config. But the current cpu in your configuration will limit the max amount of gain you would see with a stronger prosscor. However regardless of the bottleneck on the cpu you would still have a faster overall machine with one new 7970m.

 

depends on the game really. if its a processor intensive game, your CPU will show its age, but for games like MW3 you wouldn't have any problems.

 

No PSU mod for 7970M Crossfire is needed if you keep your cards and CPU on stock or reasonably overclocked settings. Undervolting the cards will further relieve any stress on your PSU. I've completed Bioshock Infinite and Crysis 3 without any power related problems with this config.

Have a look at this thread for comprehensive information.

edit: Also note than none of the users there including me are running the 330W or any mods. All results were obtained using the stock 240W.

 

But he was also talking about overclocking would this not push the power threshold if in fact he would be getting the xm branded CPU. If he would want to get the most performance out of games. Just my thoughts.

 

All users in the thread I've linked to including me are running XM CPU's. I understand your point of view and it is valid if for example he did raise the TDP to around 80 watts and gamed for an extended period of time. This would possibly result in power throttling or a shutdown. As bigtonyman mentioned it all depends on the game. If it is a CPU limited game overclocking the XM and raising its TDP to increase CPU performance would lead to throttling/shutdown but that would be at extreme levels.

I managed to get a shutdown testing Crysis 3 when running my XM at 24/24/24/24 multi's with a TDP/TDC of 90/82. Even if the PSU could manage to sustain that load for an extended gaming session with two 7970M's the temps of the CPU would increase above 90C which I personally am not comfortable with. The cooling is really good in the R2 but it was designed for a chip with a max TDP of 55W. There are mods but that's another topic altogether...

Another point to consider is what is a users perception of "performance in games". At default Dell 920XM settings which is 24/24/24/24 with 62/62 TPD/TDC (Intel's specification is 24/23/17/17 @ 55/47 TDP/TDC), Crysis 3 on the levels after "Only Human" runs at an average of 60fps on High settings with Very High Textures at 1920x1200. The earlier levels are pretty intense on any hardware and drops to around 31fps in certain areas on my machine especially in the "Welcome to the Jungle" mission when looking at the expanses of long grass.

Bioshock Infinite at Ultra settings at 1920x1200 runs at a constant 60fps. Tomb Raiders performance is also very good at Ultra settings with around 90% of the time running at 60fps apart from some areas where the fps drops to around 33fps.

All of this is with a single 240W adapter with stock Dell XM settings. The cards can potentially push out higher FPS but I always use VSYNC to cap FPS as screen tearing annoys me. This kind of performance is quite good for a laptop especially considering these are a few of the latest games.

If he wants to overclock to chase numbers he can do that as well. The 240W can sustain loads above its specs for short periods of time which is perfect for benches. It enabled me to get this 3Dmark11 score with both graphics cards overclocked to 950/1400 and the XM at 25/25/25/25 with 90/82 TDP/TDC... and did not shutdown.

Dell's 240W is a very good quality PSU and I've recorded up to 285W from it using my Kill-a-watt meter. I have the 240W that was manufactured by Flextronics but the Delta is just as good.

edit: To the OP, a 820QM will be sufficient for a single 7970M. In games you will be hard pressed to notice a difference between an 920XM and the 820QM. Again if it is a CPU intensive game there can be a difference. There's no hard and fast rule as all games are different. From my research before upgrading to 7970M crossfire the 820QM is still a very capable CPU and it will bottleneck 7970M's in crossfire but not to the extent where its plainly obvious. Have a look here to see a comparison of Crysis 2 with a 720QM vs 940XM with a single 7970M. Its not an ideal test as the user was troubleshooting but it gives you an idea of how much CPU resources are used in one of the current game engines and the actual difference in FPS.

That said, for $1500 you can purchase desktop components that will decimate anything a pimped out M17x R2 will be able to achieve.

 

Hi All

This is really great info, I looked like crazy and Im sure this info will be of great help for a lot of people!

I have decided though, and already did, buy desktop components, got the latest 7970, i7, motherboard etc, so I spent
1350 dollars without including monitor, keyboard, optic unit etc. Im looking for adding a second 7970 in a few months
when I have some more money!

So, I will be getting the parts soon and hope this was a good investment!

 

Congrats man!

Its a wise decision especially if you don't really need the portability. Hope you have lots of fun with your new kit, I'm sure you will :thumbsup:

 

Good luck with the custom build! Looking to build a new rig myself here soon.

 

I have 840qm and it runs superbly all the latest games no problemo with 7970m.
As others have said some games require cpu whilst others gpu power. Recently most games demand the gpu run full grunt whilst the occasional game eg crysis 3 will push cpu as well.

Just get the 7970m its amaxing card...
Edit: congratutz on desktop yes it is cheaper and easier on wallet.

 

Nice build ! I'm sure you'll get a LOT out of it

 

what 7970m have you got a dell one or clevo card I am looking to get two of theses?