Two midrange gpus have burst into the world in the last two months- the Nvidia GT 640M and GT 650M. They are both based on the Kepler GK107 core which menufactured in a 28nm process and have 384 shader cores and 128 bit memory interface and varies only in the core and memory speed and type.
Generally, the GT 640M offers as high as 20%-25% higher performance compared the previous generation GT 555M (1, 2) and the GT 650M offers up to 30% higher performance than the GT 640M , judging by reviews and benchmarks (1) and raw power data. Also, the GT 640M delivers averagly 20%-30% less performance (1) than the GTX 560M . This means that the GT 650M is about powerful as the GTX 560M (but it depends on the scenario). The following table shows a sammery of key data of these cores and although you can’t tell what will be the performance, it does help to confirm the performance guesses we have about the GT 650M from too few benchmarks.
|Model||Core, shaders (vertex / geometry / pixel)||memory bandwidth (GB/s)||Core speed||processing power (GFLOPS)|
|GT 640M||Kepler (GK107), 384 unified : 32 : 16 (625MHZ)28nm process||28.8 (DDR3)|
|GT 650M||Kepler (GK107), 384 unified : 32 : 16shader speed – 850MHZ (DDR3) / 735MHZ (GDDR5)28nm process||28.8 (DDR3)|
|GTX 560M||Fermi (GF116), 192 unified : 32 : 24 (1550MHZ)40nm process||40 (128 bit interface)60 (192 bit interface)||775MHZ||595.2|
As you can see, the GDDR5 version of the GT 650M has a 64GB/s memory bandwidth and 564.5 GFLOPS which is very close to the GTX 560M processing power. Although this data can’t tell it by itself what will be the performance, it does give us a clue about the potentional and, indeed, it matches the benchmarks – the GT 650M comes very close to the GTX 560M and sometimes even surpasses it, like in the case of Skyrim. Also remember that the benchmarks used in current reviews are still old Nvidia drivers and in my opinion the new Kepler might benefit from new drivers.
|Settings||GTX 560M,I7-2630QM||GT 650M 1GB GDDR5,I7-3610QM||GT 650M 2GB GDDR5,I7-3720QM||GT 650M 2GB DDR3,I7-3720QM|
|Mass Effect 3||1920×1080, all on, onAA 8xAF||~44||~46||~49||~35|
|Diablo 3||1920×1080, high, on AA||~44||~44||~41|
|Skyrim||1920×1080 Ultra Preset 8xAA 16xAF||~22||~24||~25|
|Anno 2070||1920×1080 very high onAA 4xAF||~41||~36||~36||~37|
|BattleField 3||1366×768 high -AA 16xAF||~38||~30||~34||~31|
|Max Payne 3||1920×1080 Very High, DX11 8xAF Very High FXAA||15||18|
|Dirt Showdown||1366×768 High Preset AF 2xMSAA||60||56|
You see in the table one example when the GT 650M DDR3 version outperform the GDDR5 version. This might be due to a game that (Anno 2070) needs less memory bandwidth and more processing power, which is the case of the DDR3 version (higher core clock, lower memory bandwidth). However, in most cases you should prefer the GDDR5 version. For more games benchmarks, click on the links to the full reviews.
If you check the numbers on notebookcheck benchmarks, you’ll see games, like Anno 2070, that were testes also with the newest Nvidia drivers – ForceWare 301.34. This doesn’t seem to change the results in that case, but will have to wait to thorough review of the new drivers. One more interesting thing is the use of some OC’ed GT 650M DDR3 version with 950MHZ core clock which makes it faster. The downside is, as always now adays, more heat and higher power consumption.
The fact that the raw power of the GT 650M GDDR5 version (which is the faster one) is lower than the GTX560M one, doesn’t mean that it will be slower on real world applications and games – different micro Architectures can be more efficient in a way that makes it better in real world situations depite the raw power, which seems to be also the case here. Moreover, it depends on other factors too, like the cpu and drivers in test.
Taking into account that the GT 640M and GT 650M is menufacured in a 28nm process and should have a lower power consumption than their 40nm competitors from the 5XX Nvidia series and so they should be much more attractive to the laptops market.
Currently, not many laptop equipped with the GT 650M and GT 640M, but in the following months will probably see more and more. HP (GT 650M), Sager (GT 650M), Lenovo (GT 640M) already have some updated models.
Question 1: GT 650M vs GTX 560M?
Answer: In short, with the GT 650M you can pay less to get the same or almost same performance level. You should look for these laptops. However, you better wait for the new laptops to come, with the Ivy Bridge cpu and new gpus from Nvidia or AMD.
Question 2: GT 555M vs GT 640M?
Answer: definitely GT 640M, for the same price. The current AMD direct competitor is the 7690M and it’s not faster than the GT 640M, so in that manner you don’t have to worry. However, you better wait for the whole series of CPUs and GPUs to come out so the prices and laptops will be more competitive.