Is the Radeon HD 7850 more powerful than the GTX 650 Ti Superclocked even though the GTX has better clock speeds?
I just got the EVGA 650ti Boost SC and I couldn't be happier. In all the benchmarks I looked at it performed as good as or better than the HD7850 and it's only $179.99. So if you're on a budget and you want a great card for the money I highly recomend it.
Thanks :)
Yes, the memory bus is wider (256 bit), thus the 7850 performs better, whatever the clock speed of the 650ti (only 192 bit just like 650 ti boost or 660, which is still better than the 128 bit memory bus width of the 650). Plus the 7850 can be overclocked to 1050 MHz out of the box, without any additional costs, and at that speed, it seriously pummels the 650ti, and is still well within thermal spec.
The GPU itself only determins the number of pixels per second can be calculated, but with modern display resolutions, these pixels need to be stored really quickly somewhere while the frame is calculated and offloaded really quickly to the display. The higher the resolution or the faster the GPU, the more important the memory bus width becomes. That's why with the latest drivers, that are ever better optimised for ever more games, AMD often still has some headroom for performance increase and pulls away from similarly priced nVidia cards, because nVidia only has a maximum 192-bit wide memory bus for the GK106 GPU's (up to GTX 660 retail version, some OEM GTX660 are GK104 based and have a 256-bit bus and 50% more transistors, those will perform better). The difference in bus width makes for a speed loss of 64 bits (256-192) per cycle, and that DDR5 VRAM clocks around 1.45 x10^9 cycles per second, with a screen pixel taking 32 bits, so that's a good 700 million (7x10^6) pixels per second less throughput. The extra throughput is not as measurable in traditional average fps benchmarks, but in real life, having that extra memory access, makes the critical refresh rate (the mimimum fps) a lot better, everything looks much smoother on a graphics card with a wider memory bus.
Thanks thats really helpful! So you would definatley recomend the radeon 7850 over the GTX 650 Ti Superclocked?
+ you can do crossfire on the 7850, and yeah, it's not even overclocked.
and thank you soltan, that was very helpful!
Yes, I would definitely recommend the 7850 with 2GB of VRAM and 2 fans:
- 2 GB is the ideal VRAM size for FullHD up to dual FullHD screen resolution. With only 1 GB of VRAM, you'll lose a lot of speed in critical refresh conditions because the GPU can process a lot of pixels that cannot be stocked in VRAM, so when you have for instance a very intense graphical scene with a lot of dynamic lighting, texels, blur effects and stuff, and you pan really quickly, the GPU can calculate all the pixels needed to do that at high framerate, but the VRAM needs to refresh a much larger chunk of pixels, so that will eat up a lot of the GPU's resources, and you'll have stuttering or at least a serious dip in your framerate.
- the 2GB variant of the 7850 card is 4k ready, and with the 4k screens expected to hit the below 1000 USD mark by the end of this year, 4k media will come really fast, and it's good to have a potent 4k card to play back 4k media.
- also 2 GB VRAM because some OpenGL/OpenCL enabled applications, e.g. Darktable, can only see half of the card's memory because of the pretty ugly OpenGL/OpenCL drivers AMD has provided, which is one of the big problems with Apple systems, that use a lot of AMD GPU's and are often used in the graphic design and -production industry. Now Apple has applied a patch, so that the full memory size is addressable, but the downside is that because of that, OpenCL runs a lot slower, sometimes even slower than not using OpenCL on the GPU but letting the CPU do all the work. An application like Darktable requires 1 GB of VRAM on the GPU card to enable OpenCL, so you need a 2 GB card so that OpenCL works, and then it will work normally, but when you have a 1 GB card, it will only see 512 MB, and will not enable the OpenCL functions, making the application many times slower. The patch for this AMD OpenCL problem will not be immediately available, because AMD has very limited resouces for this (AMD cards are much more expensive to make than nVidia cards, and AMD doesn't have any foundaries of it's own, so they lose money on every CPU or GPU they sell, they have to invest enormously in marketing like the Never Settle Reloaded promo, they are doing a lot of work on their drivers for Windoze games and their basic linux drivers, and they've already laid off all the staff they can, they are completely running on reserves), and has other contracts that provide in the ability by OEM's (Sony, MicroWTFt) to provide their own low level solutions. So the only pressure they get is from the UNIX/Linux/MacOS world, and that's just much smaller market for AMD so it gets no priority. They have however sided with Adobe, and Adobe has the resources to provide a solution, but it will take some time, as the collaboration has only started a few weeks ago.
- 2 fans because it will prolong the lifespan of your card considerably and make a lot less noise, because two fans cool better than one and they run at a lower speed, saving the barings and making less noise, plus a two fan solution cools more evenly than a single fan solution and loses less efficiency with dust.
HD 7850 is an all round better card. I've got a GTX 650 Ti, it was a bad purchase, a HD 7850 can be bought for little extra money + it's much more powerful. AMD has an advantage over Nvidia at the moment when it comes to bitcoins, too.
Thanks so much for taking the time to write all this out its been really helpful.
Thanks im definatley getting the 7850 now.
Thanks! Stuff like this makes me love electronics even more.