The best card under $160.9, but it still
underpowered
Wild bunch: 15 – 20 per cent faster than a
GTX 650 1GB; costs only $144.5
Munch bunch: Still struggles at 1,920 x 1,080
with 4x AA
How much?
Typical street price: $144.5
Manufacturer: www.amd.com
AMD
Radeon HD 7770 1GB
Like much of AMD’s current line-up, the HD
7770 1GB has received a healthy price cut recently, in addition to driver
performance updates. Now available for around $144.5 for a stock card, it goes
head to head with the GTX650 1GB; a card which, on paper, it comfortably beats.
The HD 7770 1GV uses AMD’s Cape Verde XT
GPU. While it’s based around the same core architecture as its more auspicious
siblings, Cape Verde is a significant reduction, with just a single front-end
engine. This means that it sports just a single tessellation unit and
rasterizer.
Ten CUs, each with four SIMDs, results in a
total of 640 stream processors, alongside 40 texture units. This is almost a 40
per cent drop in the number of SPs from the HD 7850 2GB’s GPU, but the impact
is lessened by an increase in core frequency, with a stock HD 7770 1GB running
at 1GHz. The reduction in stream processors also sees Cape Verde XT’s 1.5
billion transistors squeezed onto a 123mm2 die, making for a maximum
TDP of 80W. the card still requires a 6-pin PCI-E power connector though.
However, it’s hard to see a silver lining
around the reduction in the number of ROPs to just 16, and the use of just two
64-bit memory controllers, resulting in a running a t1,125MHz (4.5GHZ effective),
the HD 7770 1GB boasts just 72GB/sec of money bandwidth 8GB/sec lower than that
of the GTX 650 1GB.
That said, the Unigine Heaven benchmark
score of 691 clearly demonstrates the HD 7770 1GB’s advantage over the
similarly priced GTX 650 1GB, and it also proved faster than the budget GeForce
card in every benchmark. In Battlefield 3 at 1,920 x 1,080 with 4x AA, the HD
7770 1GB managed a minimum frame rate of 23fps compared to the GTX 650 1GB’s
20fps, although this is still below the playable barrier. Meanwhile, in Skyrim
at the same resolution, the 7770 1GB was 25 per cent faster thanks to a minimum
frame rate of 34fps. The HD 7770 1GB was more power-hungry, though, pulling a
peak system load of 145W compared to the GTX 650 1GB’s 126W.
Conclusion
The HD 7770 1GB comprehensively outclasses
the GTX 650 1GB which, thanks to AMD’s price cuts, is now its direct
competitor. In all of our tests, the Radeon card proved quicker by a healthy
margin, but as with the rest of the low-end cards, it still represents poor
value for money compared the those that cost 50 per cent more. An HD 7850 2GB
is 80 – 90 per cent faster in most circumstances and, while we recognize that
you may be reluctant to spend more than $160.9 on a GPU, the benefits far
outweigh the additional expense.
Scores: AMD
HD 7770 1GB
·
1920 speed: 7/20
·
2560 speed: 5/20
·
5760 speed: 1/5
·
Value: 45/55
Nvidia GeForce GTX 650 Ti 1GB
Fills a gap, but the HD 7850 2GB is worth
the extra $40
Vip: Halfway point between mid-range and
low-end; decent BF3 performance; playable frame rates at 1,920 x 1,080
Seat filler: HD 7850 2GB is a lot
quicker and only $40 more expensive
How much?
Typical street price: $185
Manufacturer: www.nvidia.com
Nvidia
GeForce GTX 650 Ti 1GB
With a $144.5 gap between Nvidia’s
excellent GTX 660 2B and the low-end GTX 650 1GB; it’s no surprise to find the
green team producing a middle-ground competitor. With prices starting at $185
for stock models, its price is certainly leaning more towards the low end of
the market though.
The GTX 650 Ti 1GB’s GK106 GPU has made a
number of cuts to enable the lower price. One of the card’s five SMs has been
disabled, but this can be from any of the card’s three GPCs. While this can
mean that some cards ship with an extra rasteriser (due to the higher GPC count),
Nvidia tells us that performance is SM-limited, so there’s no difference.
Four SMs provide a healthy count of 768
stream processers, 64 texture units and four tessellation units as part of each
SM’s polymorph engine. These figures are surprisingly beefy when you consider
the $104.5 price difference between the GTX 650 Ti and the GTX 660. The former
doesn’t benefit from GPU Boost, though, and uses a static stock core frequency
of 925MHz.
Deeper cuts were made to the memory
interface and ROP count. One of the GPU’s three 64-bit memory controllers has
been disabled, dropping the memory interface to 28-bit and the ROP count to
only 16 – just like the GTX 650 1GB. A stock memory clock of 1,350MHz (5.4GHz
effective) makes for an effective memory bandwidth of just 86.4GB/sec.
As this card launched just before this
issue went to press, we’ve only been able to test a $225 factory-overclocked
SKU of the card; stock model will typical be around 10 per cent slower, so bear
this in mind when looking at the performance figures.
The GTX 650 Ti’s Unigine score of 903 is a
sizeable improvement over the HD 7770 1GB’s 691, with the GTX 650 Ti 1GB also
boasting a substantial performance advantage is real-world games. In Skyrim at
1,920 x 1,080 with 8x AA, the GTX 650 Ti 1GB produced a minimum frame rate of
45fps compared to the HD 7770 1GB’s 34fps. However, the HD 7850 2GB, which
costs just $32 more, offers a large step up, with a minimum frame rate of 53fos
in the same test. Our factory-overclocked GTX 650 Ti also managed to
comfortably produce playable minimum frame rates in out other test games at
1,920 x 1,080.
Conclusion
The GTX 650 Ti 1GB finds itself between two
worlds. It’s certainly faster than the sub-$144.5 low-end cards, but also
substantially slower than the mid-range delights of the HD 7850 2GB. It’s a GPU
that’s been made to hit a price point, and while a $185 price may appeal to
gamers on a budget, spending an extra $40 and grabbing an HD 7850 2GB is a far
better decision.
Scores: Nvidia GTX 650 Ti
·
1920 speed: 9/20
·
2560 speed: 6/20
·
5760 speed: 2/5
·
Value: 41/55
