Radeon 7770 vs Radeon 6850 vs Nvidia GTX 650 ti vs.

schulmanworks

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maxalge

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7770 = 6850 < gtx 650 ti.


I would get this version:

http://www.asus.com/Graphics_Cards/NVIDIA_Series/GTX650TIO1GD5/

http://pcpartpicker.com/part/asus-video-card-gtx650tio1gd5

 
The Radeon 7770 doesn't need to be overclocked to meet the Radeon 6850. The GTX 650 Ti is somewhat faster on average and the Radeon 7770 would need a decent over reference frequencies (~15-20% should do it) to meet the GTX 650 Ti. However, in higher quality settings, the gap between the GTX 650 Ti and the Radeon 7770 and Radeon 6850 dwindles due to the GTX 650 Ti's memory bandwidth not being high enough to feed its fast GPU to beat the GPUs in the Radeon 7770 and 6850.
 
^This. With driver optimizations, I believe the HD7770 is now essentially as fast as the HD6850, but it is still generally slower than the GTX650Ti. It's enough of a difference that each of them gets a recommendation in Don's monthly Best Graphics Cards... article. My question though is, why would you be willing to OC a HD7770 but not the GTX650Ti?
Personally, having had 2/4 fail within hours or days of first use, I am not comfortable recommending Asus graphics cards (as much as I love their mobos). I'd choose MSI, XFX, Sapphire, or HIS, but NOT the cheapest models of any of those, all of which I've heard (or seen in reviews) to have "issues" such as inefficient iron core chokes, cheap fans and plastic shrouds, and/or noisy coolers.
 
Well, for the cheaper models, AMD cards tend to overclock very well whereas Nvidia models are often best left at or near stock unless you get a good model. Nvidia models are also all voltage locked and every few Nvidia driver releases seems to have a version that slightly increases overclocking instability these days. I've been in way too many forum threads talking about Nvidia's latest drivers causing overclocks to need to be dropped somewhat with every few releases to stop crashes and other issues.

On the other hand, the GTX 650 Ti doesn't need much of a GPU overclock; it simply needs a good memory overclock to get great performance improvements. There's a lot of memory frequency headroom to be had if it can get anywhere near the memory frequencies of its bigger brothers. If it can get at least about 1.7GHz on the memory, then it will near the Radeon 7850's stock performance whereas the Radeon 7770 would struggle to get near there.
 

schulmanworks

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So what about the 6850? Or a 6870 http://www.newegg.com/Product/Product.aspx?Item=N82E16814150561&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&AID=10446076&PID=3938566&SID= it's on par with the price of the 650 ti after rebate. And what's the difference between a gpu overclock and a memory overclock?
 
I wouldn't get a Radeon 6850 nor a Radeon 6870. Newer cards such as the Radeon 7770 and GTX 650 Ti are better options because they are far more power efficient and if you're interested in overclocking, their better overclocking headroom is also of interest.

There are two main frequencies that you control on a graphics card. They are the GPU frequency and the memory frequency. The first is the frequency used by most parts of the GPU (the processing chip on the graphics card that the graphics card's cooler is meant to cool) and the second is the frequency of the memory interface connected to the GPU. Increasing memory frequency increases the bandwidth between the memory and the GPU whereas increasing the GPU frequency increases the number crunching performance of the GPU.

The GPU of the GTX 650 Ti is very powerful compared to its memory bandwidth, so increasing the GPU frequency doesn't improve gaming performance as much as it does on the Radeon 7770 which has a much weaker GPU, but similar memory interface. Increasing the memory frequency of the GTX 650 Ti is a much more effective way of overclocking the GTX 650 Ti due to the memory not being fast enough for the GPU to stretch its "muscle".
 

The 7770 doesn't have more overclocking headroom than the 6850. Probably the other way around actually. But still, the 7770 is way more power-efficient and by now it's cheaper as well.
 


It does have better overclocking headroom according to my testing of them, granted I haven't tried many model nor have I tried after-market coolers on them. Radeon 6800 generally wasn't really a top overclocking series, unlike its GTX 460/560 competition and the newer Radeon 7000 cards with GCN GPUs. The 7700 series doesn't do as well as the 7800 and 7900 series in overclocking from my experience with them, but the 7770 does seem to do better overall than the 6850.
 

What? The 6850 overclocks very well. Unless you get a bad sample you're pretty much guaranteed to reach the 875 MHz Overdrive limit at stock voltages. With voltage tweaking you're bound to get well past 900, and some can break the 1 GHz barrier.
 


That's not overclocking very well compared to what the Nvidia competition of its time could do nor against what today's models can do. The Radeon 7770 overclocks just as well by percentage on the GPU, gets more efficient gains per MHz, and also gains more from memory overclocking compared to the Radeon 6850's gains from memory overclocking.

The Radeon 7850 is far more capable at overclocking than even the Radeon 7770 and even it is overshadowed by the Radeon 7950. Both the Radeon 7850 and the Radeon 7950 have fairly similar stock frequencies on the GPU to the Radeon 6850, yet both can often get close to or beyond the 1GHz barrier without voltage tweaking and far beyond with it while having very efficient gains per MHz of the GPU frequency.
 

That's close to how well the GTX 460 overclocked (25% typically) and equal to or slightly better than the GTX 560 (which could also get to near 1 GHz, but had a higher reference clock than the 6850).

The 7770 doesn't overclock past about 20%. In fact, Tom's only got to a 15% core overclock.
 


My experience with the GTX 460 and 560 showed much higher overclocks than compared to Radeon 6800, as did most other people who I've talked to or even simply read about it.

I've had experience with dozens of 7770s (although, still, a low number of models) in builds that I've done with or for my clients. I think that I can provide a better example of the norm than Tom's with a single 7770 test from almost a year ago with far different drivers and less of an attempt at max overclocking than just getting a decent boost IIRC.
 


Yes, I am including the 6870. The 6850 overclocked about as far as the 6870 in my experience, so I wouldn't leave out the 6870 in any discussion about the 6850's overclocking potential. Like you said, the 6850 had more headroom because it started at a lower point and reached fairly similar limits to the 6870. All on average of course, there may have been a few outlying cards from each.