AMD Radeon HD 7750 & Radeon HD 7770 GHz Edition Review: Evading The Price/Performance Curve
by Ryan Smith & Ganesh T S on February 15, 2012 12:01 AM EST- Posted in
- GPUs
- AMD
- HTPC
- GCN
- Radeon HD 7000
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.
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tipoo - Wednesday, February 15, 2012 - link
I probably won't be enticed into a video card upgrade until the next generation of Microsoft and Sony consoles are out. In the land of console ports, even a 6770 can run nearly everything comfortably at most common monitor resolutions.Movieman420 - Wednesday, February 15, 2012 - link
I have an OCd C2D Wolfdale running the 4850 and I also agree that the 4850 will go down as one of the best bang for the buck cards ever.My current i5/Z68 rig is running what I think will be considered another BBFTB card...the 6850...the dual fan Gigabyte 685OC in my case.
The 5770/6770/7770 are a fantastic line of mid-range cards...esp OCd but for a few $$ more an OCd 6850 still holds it's own quite well, there's no real counter for a 256bit vs 128bit memory bus. A big hats off tho to the 7770's high res numbers...pretty damn sweet, but I don't need uber res for a 23.5 inch monitor...ofc I'm not a hard core gamer either.
cjs150 - Wednesday, February 15, 2012 - link
7750 seems perfect for an HTPC. But to put it into context, IGPs should be using the 7750 as the benchmark for what to aim for. Can see this becoming completely obselete very soon once products based on Raspberry pi or Cu Box get released and match (the very impressive) picture quality of the 7750. In mean time get a low profile passive cooled version out and it will be perfect.As for the 7770 I simply see no purpose for it at all. NVidia 560 is only marginally more expensive and beats it completely. 7770 seems to me to be a complete waste of stock
Shadowmaster625 - Wednesday, February 15, 2012 - link
So the 7770 should be at $109, and that forces the 7750 down to $89 or less. The die sizes on these chips are a lot smaller than their competition so I dont see what AMD is thinking. Inflation? lol.Shadowmaster625 - Wednesday, February 15, 2012 - link
Why would a 7750 consumer 3 watts less than a 7770 during the "long idle" state. That really makes no sense. During that state there shouldnt be any difference at all between the two cards.tipoo - Wednesday, February 15, 2012 - link
It has over 100 more stream processors? 3W is pretty minuscule.akbo - Wednesday, February 15, 2012 - link
They are using a gorram 1200W PSU and those have s*** efficiency at 10% load. 3 watts means that it may pull about 1 watt more on-chip.KompuKare - Wednesday, February 15, 2012 - link
Which begs a simple question that has been bothering me with Anandtech GPU reviews for a while: how come they don't measure the wattage for the cards rather the whole system. Ok, it needs a custom PCI-E riser board and a multimeter but other sites (like techpowerup.com or this French site (can't think of it ATM) where the place I first saw that method used) manage it.Or at a minimum why is there no IGPU (Intel 3000) power usage in the review to act as a baseline?
Death666Angel - Wednesday, February 15, 2012 - link
I'm kinda disappointed by the 77xx launch. I'd have hoped for some €150 - €200 cards, consequently performing better than the 6870. Maybe the 78xx will be better. I really hope nVidia comes around with good cards, that way the consumer won't get ripped off. Although I also hope that AMD makes some money in the mean time.geniekid - Wednesday, February 15, 2012 - link
I just want to reiterate how much I appreciate the games you've chosen for your benchmarks. It's a very diverse set of games and covers a lot of the non-FPS genres that other review sites tend to leave out.