AMD Radeon HD 7970 Review - CPU Comparison w/ Core i7-920

Submitted by skipclarke on 22 December, 2011 - 17:18

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As part of this review, I updated by benchmark rig from a Core i7-920 to a Core i7-2600k. I felt that I was hitting a CPU wall in some instances, mostly in widescreen resolutions. Before I dismantled the i7-920, I put together a few benchmarks with the HD 7970, the 6970. Below are comparison charts for the seven titles that make up our current review stable. Overall, the CPU upgrade shows a weighted improvement of 8% in widescreen, and an improvement of 4% in Eyefinity.



As part of my rig overhaul, I only went back to retest the Radeon HD 6000-series. To provide a glimpse of the improvements compared to the Radeon HD 5870, I ran one set of tests using the Radeon HD Eyefinity6. I chose this one card as I has a 2GB frame buffer, and offers a better comparison to both the HD 6970 and the HD 7970.

Looking at a total weighted average, the Radeon HD 7970 is 43% faster than the HD 6970 in widescreen, and 79% faster than the HD 5870 E6. For Eyefinity, the Radeon HD 7970 is 46% faster than the Radeon HD 6970, and 91% faster than the Radeon HD 5870 E6.



I've seen lots of CPU reviews that look at tons of synthetic benchmarks, and churn out numbers based on things such as Prime95. For something highly multi-threaded like those synthetic benchmarks or video encoding, adding cores or a few fractions of a GHz produce a measurable improvement. But the reality is that games aren't that highly multi-threaded, and are often far more GPU bound than CPU bound - especially for Eyefinity.

My upgrade from the original low-end Core i7-920 to a high end Sandy Bridge chip (the 2600k) produced minimal improvements. And, the instances where these improvements were most often noticeable were in widescreen. But really, is it worth it to upgrade both CPU and motherboard (and possibly RAM) to take HAWX 2 from 129fps to 143 fps? From a base frequency standpoint, I would have suspected taking four cores from 2.6GHz to 3.4GHz would have produced better results. Simply put, it didn't. Your money is better spent on upgrading your GPU.

In perusing the net for some CPU reviews to read, I was shocked to find that a major site such as AnandTech was still using a Radeon HD 5870 for testing their "gaming performance", even on the new Sandy Bridge-E. Really? To get a good view of gaming performance you've got to match the CPU to the GPU, and I think they are doing a disservice to their users by being now two generations behind. Granted the HD 7970 was just released, but I would have expected them to update their rig to an HD 6970 or something similar a long time ago. Looking at PC Perspective, I found a similar situation where they tested the i7-3930k with an NVIDIA GTX285. We are well into two generations back.

I don't point this out to take a shot at AnandTech or PC Per (not like a major site like that would notice a critique from a smaller site like the WSGF). However, I do want to point out that when you're looking at hardware reviews, you need to ensure that you're getting a good "real world" review. This is what we strive to do here.