Understanding Video Cards

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Level 1

23 points

Understanding Video Cards

Simply put, I need a decent understanding of the video card differences in the last 2 versions of the iMac line. While I don't do a lot of high visual rendering or anything, however I do play an awful lot of Team Fortress 2 on Win 7 boot camp because the graphics get quite choppy when run on OS X. I do some light video editing. I am getting the new iMac and am trying to weigh the video card differences.

(Keep in mind that this isn't a matter of cost, bad feelings, or anything else besides what you see here.)

My current 27in upgraded iMac has: AMD Radeon HD 6970M 2048MB

The new 27in iMac has: NVIDIA GeForce GTX 675MX 1GB GDDR5

The new 27in upgrade iMac has: NVIDIA GeForce GTX 680MX 2GB GDDR5

The most obvious difference from I can tell right here is the 2GB RAM in my current machine (which was CTO) and that all the new iMacs come with 1GB RAM with no option to upgrade that except the highest end iMac. I'm assuming the sheer RAM capacity is a huge differenciator in the matter?

What about the cards themselves? Is there a small/large difference based on the card specs/achitecture alone?

While I know a decent deal about hardware, the GPU is the area I never really cared about...until now.

Thanks!

Posted on Dec 6, 2012 11:13 AM

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Answer 1

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thetimeparadox

Level 1

121 points

Dec 6, 2012 12:03 PM in response to Zathrak

The AMD Radeon HD you mentioned is slightly slower than the GeForce GTX 485. The GTX 680 on the high end imac is roughly twice the performance of the mentioned card. So you would get a significant graphics performance increase. However, the GTX 765 on the low end imacs are also very good, and would still be a significant increase in performance. You can compare the performance of the cards here...

http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-680/performance

hope this helped.

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Answer 2

Zathrak Author

Level 1

23 points

Dec 6, 2012 12:19 PM in response to thetimeparadox

Thanks for the quick reply! I think I might be reading this wrong.

My interpretation of what you said is that the NVIDIA GeForce GTX 680MX 2GB GDDR5 (new, upgraded iMac) is about twice the performance (however that may be defined) as the AMD Radeon HD 6970M 2048MB (my current iMac). If that's the case...

1) I understand that there would be a significant increase from what I've got (AMD Radeon HD 6970M 2048MB) to what's in the new upgraded iMac (NVIDIA GeForce GTX 680MX 2GB GDDR5). Where does the new, non-upgraded one fit in this equation (NVIDIA GeForce GTX 675MX 1GB GDDR5)? I didn't see the GTX 675 on the chart in the link but would assume it's just under the 680 suggesting a minimal difference outside of the RAM increase?

2) Segway to RAM, what does the 1GB vs 2GB effectively do? How does one determine if they need 2GB of RAM and how does that play in to the situation?

More-less, I'm hoping that the increase in performance will be enough for TF2 and light video editing even if it's just the standard 675 1GB. That's not to say that other features like the i7 won't sway me over to the upgraded high end iMac. Make sense?

Thanks again!

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Answer 3

Dec 6, 2012 12:23 PM in response to Zathrak

Your interpretation is correct. 1: essentially more breathing room. 2) More VRAM allows the process to spread out on the card and causes less stress to the heating system at high loads. For Team Fortress 2, even the low end is fine (have played it).

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