NVIDIA's desire to cover as much ground on the market as possible with a relatively low number of chips has resulted in the split of a single chip between desktop and notebook hardware. The first GPU based on the Kepler architecture which we had the chance to test was, indeed, GK107. More interestingly, this chip was housed in Acer’s TimelineU ultrabook, labelled GeForce GTX 640M. Afterwards, GK107 appeared on a few other mobile graphics cards, the most interesting of which is GT 660M. Since then, NVIDIA has transferred exactly the same GPU in discreet graphics cards onto the desktop market.
We’re dealing with Zotac’s model today, which is very similar to NVIDIA’s referent GTX 650. This model is positioned just below GTX 660, but interestingly enough, the lacking range of chips has resulted in a pretty notable performance gap. Unfortunately, even on paper, these two cards are hugely different, and on the hardware level, GTX 660 is more than twice as powerful as GTX 650. This means that GTX 650 won’t be facing HD 7850, or even HD 7770, but HD 7750, which implies that NVIDIA has done a weak job in covering the mid-range, leaving a gaping hole that only benefits the chief competitor. AMD maintains a very well-suited offer, despite the early presentation of the Southern Islands family, with no significant discrepancies or irregularities between models, and certainly no collisions in pricing policy. The way things are today, it seems not only that NVIDIA hasn’t had such a structured approach, but also that the company hasn’t given such a thing even a minute’s attention.
GeForce GT 660M on steroids
Looking at the specs of GTX 650, one gets the impression that it’s little else than a seriously overclocked GT 660M, the best Kepler card available for the mobile segment. That impression is entirely correct – other than the substantially higher clocks, these two cards are identical, as both are based on the GK107 GPU manufactured in TSMC’s 28 nm production process. Its surface and energy efficiency are highly regarded, especially if you have a look at the fantastic performance of the latest GeForce mobile GPUs. However, the desktop segment is always another story, since it’s not as power-conscious, focusing on performance instead. GK107 has a single GPC that consists of two SMX. Since each of the latter has 192 stream processor, the total number amounts to 384. This is great for mobile GPUs, but not as stellar in the hard desktop competition. The number of texture units per SMX is 16, so the total is 32.
Interestingly enough, Radeon HD 7750 has the same number of TMUs, and both cards have 16 ROPs as well. NVIDIA has seriously upped the clocks, though, with the core clock at 1058 MHz. The GPU is surrounded by four GDDR5 memory chips. These form a 128-bit bus, just like this card’s direct competitor. Even with the effective clock of 5 GHz, the bandwidth is relatively small at 80 GB/s, but with the GPU’s modest “firepower”, this isn’t likely to be an issue. NVIDIA is aware of this as well, so they assigned a total of 1 GB RAM, which should be enough for the proposed expected resolutions of 1366x768, 1600x900 or 1680x1050, as this card isn’t targeting users who hope to play in full HD resolution or maximum detail levels. Furthermore, GK107 has shown in its mobile rendition that it doesn’t cope with full HD resolution too well, which further positions this card. Honestly, we can’t escape the impression that this card would be much better off with a suffix like GT or GTS than GTX, which suggests top performance in a given class.
As for the card itself, it’s signed by Zotac, and has a few details that make it recognisable in the lot. Its looks are pretty simple, with the dominating orange fan. The plastic shield conceals the aluminium body, cooled by the active element. There’s nothing to reproach in the output department, with two DVIs and one HDMI connector. Some may desire a DisplayPort, but this is unlikely to be a major drawback even for those users. Although GTX 650 is power-conscious, one 6-pin molex connector was still required, probably due to the higher clocks that necessitated extra power. The power unit is very simple, and noise filtering is done in only two phases, although this is more than enough for a graphics card with about 63 W of TDP. Zotac has also minimally overclocked the GPU, from 1058 MHz to 1071 MHz, which isn’t something to truly give the card an edge. The memory works at the referent values, so no changes in that department.
Better as a notebook chip
Few will be surprised by our impression that this chip was much better-suited to notebooks, as we’re all familiar with Kepler’s success on the mobile market. That said, we’re sorry to see that replacements to the old Fermi are inadequate. As for GTX 650, the GK107 on it doesn’t really shine. Temperature and power consumption are excellent, but performance is simply lacking.
|Card||Zotac GeForce GTX 650||AMD Radeon HD 7750|
|Test Results||1680x1050 0xAA 0xAF / 1920x1080 0xAA 0xAF
|Clock(GPU / MEM)||1124MHz / 1250MHz (effective 5GHz)||830MHz / 1125MHz (effective 4.5GHz)|
|Futuremark 3DMark 11 (performance preset) GPU Score||1901 / 1444||1636 / 1218
|3DMark Vantage (high preset) GPU Score||8688 / 7614||6470 / 7406
|Unigine Heaven 3.0 (DX11, high, tesselation off) [fps]||42.1 / 37.1||39.3/ 34,5|
|Crysis Warhead (DX10, gamer) [fps]||25.6 / 21.9||36.5 / 32.2
|Crysis 2 (DX11, Ultra, HD Textures) [fps]||38.8 / 33.4||31.3 / 27.2
|Metro 2033 (DX11, high, tesselation) [fps]||38.7 / 34.7
||35.7 / 32.1
|AvP DX11 (DX11, max) [fps]||23.1 / 21.9||19.9 / 17.6
|F1 2010 (DX11, ultra) [fps]||37 / 34||36 / 33
|Dirt Showdown (DX11, high) [fps]||54.6 / 50.1||63.3 / 56.5
|Sniper Elite V2 (DX11, medium) [fps]||27.2 / 23.9||33.4 / 29.4
|Sleeping Dogs (DX11, High) [fps]||25.9 / 22.9||27.7 / 24.1|
|Test Platform: Intel Core i5 760 @ 3.8GHz, 2 x 4GB AMD Memory 1600MHz DDR3, ASUS Maximuss III Extreme, WD 500GB, Windows 7 64bit Ultimate, ForceWare 306.02 Beta, Catalyst 12.8
Although the card is well-balanced in itself, it’s very difficult to embrace its GTX suffix, to the point of questioning whether it deserves it at all. We don’t think so, as it honestly belongs to the low-range, and we wouldn’t be surprised to see integrated GPUs surpassing its performance in a few years. All in all, solid performance that’s still sub-par compared to direct competition at a similar price don’t give us too much room in pronouncing the verdict. Being late to the market, and with an inadequate solution at that, is hardly the best way of winning anyone’s heart.
|Zotac GeForce GTX650||AMD Radeon HD 7750|
|GPU Clock [MHz]||1124||830|
|ROP / Texture units||16/32|
|Mem. type/ Capacity/ BUS width||GDDR5 / 1GB / 128|
|Memory clock / effective clock [MHz]||1250 / 5000||1125 / 4500|