Theoretical Performance

Before moving on from compute performance, we wanted to quickly take a look at theoretical performance. Identifying the theoretical performance of the 7700 series in relation to other cards may help explain why it’s often trailing the 5770 and 6850.

A quick look at texture fillrates gives us our answer for the 7750: it has even lower texture performance than the 5750, never mind the 5770. Thankfully very few games are heavily texture bound these days – and if they were the 7750 likely wouldn’t have enough VRAM for them anyhow – but the massive gap in theoretical texture performance between the 7750 and7700 means that the 7750 is behind virtually everything else.

Conversely if you look at the pixel fill rate it’s almost identical to the 7770, which in turn trails the 5770. However in this case the 3DMark Pixel Fill test appears to be heavily memory bandwidth bound, which is why it trails the 6870 by so much.

Moving on, looking at tessellation performance is both good and bad for the 7700 series. With a maximum of 1 triangle/clock, GCN’s tessellation improvements can only do so much. It’s enough to vault past the 5770, but the 6870 still has better tessellation performance even with its lower clockspeed. Given AMD’s use of off-die buffering, it’s entirely possible we’re looking at a memory bandwidth constraint here.

Unigine Heaven backs these findings and then some. Tessellation performance is improved relative to the 5700 series, but at best the 7700 series is only going to catch the 6850.

Compute Performance Power, Temperature, & Noise


View All Comments

  • faizoff - Wednesday, February 15, 2012 - link

    I thought the 7770 would outperform the 6850 at least. Great review. Reply
  • sigmatau - Wednesday, February 15, 2012 - link

    For AMD cards, you look at the second number to indicate performance. An 8 series card like in the 6850 usualy performs as well or slightly better than a next generation 7 series card like the 7770.

    The 3rd number also indicates performance, but not nearly as much as the second number.
  • TerdFerguson - Wednesday, February 15, 2012 - link

    er, not really. A 58xx is faster than a 68xx. Reply
  • sigmatau - Wednesday, February 15, 2012 - link

    The 68xx series introduced an anomaly in the formula. But generaly what I stated is true. Reply
  • CeriseCogburn - Saturday, March 10, 2012 - link

    The anomaly here is the NVIDIA Gtx460 SMOKES the 7770 on everything, in every test, and costs 33% less.
    I see the crazed fan base cannot bring themselves to say it.
    I'll say it - 19 pages unsaid, over a long time.
  • Spunjji - Thursday, June 21, 2012 - link

    My word you are tiresome. Reply
  • nissangtr786 - Thursday, July 5, 2012 - link

    Using your logic a gtx 580 smoke the gtx 460.

    The reason why 7770 costs a bit is because its new technology, power consumption goes down quite a bit. Compare the card to same power consumption of new generation card maybe a 7870 and the 7870 will smoke the gtx 460.

    perferformance per watt 7770m smokes the gtx 460.
  • lambchowder - Thursday, November 1, 2012 - link

    you seriously need to stop posting. everything you post comes off as rabid nvidia fanatic, because you evidently are one, and you seem to camp outside these benchmarks to say the same thing everytime!! "this thing SMOKES~~~~!! the 7770!!! thats all i look at are the frame rates!!! i dont take anything else into consideration cause im an nvidia superfan" Reply
  • Beararam1 - Thursday, February 16, 2012 - link

    Really? I thought the 6870>5850. No? Reply
  • CeriseCogburn - Saturday, March 10, 2012 - link

    This 7k series needs some
    LOL - How low can you go amd ?
    Seems like more firings and cullings are in the works - or perhaps they already dragged the cat in and are now stuck with perverts.

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