Good price, good clocks, good performance... is Sapphire's latest too good to be true?
Sapphire has long been known as something of a gem amongst other manufacturers; the company pumps out reference cards for prices as close to the lowest out there possible, and still manages to deliver high-performing overclocked cards too. This one is based on the reference design of the HD4890, which we first had a look at here and the price is typical of Sapphire, sitting in as the cheapest offering out there.
Based around the 55nm RV790XT core, there are 800 shader units clocked at reference speeds of 850MHz. Each of these units are essentially a mini-processor, and they all function as one collective 'whole' to chew their way through highly-threaded apps (it just so happens that games are one of the best uses for them). These are coupled with a 256-bit memory bus that is hooked up to 1GB of GDDR5 clocked at 975MHz, which is quad-pumped to give an effective speed of 3900MHz. In other words, a phenomenal amount of memory bandwidth that can keep the shader units more than full with data to work through.
Thanks to the Decap ring of transistors around the RV790XT core, the clock speed can be pushed even further; when overclocking we managed to push the GPU all the way to 995MHz! Amazingly we almost hit the 1GHz barrier <i>on the stock cooler,</i> and we could even up the memory speed to 1060MHz for an effective speed of 4240Mhz. This is incredibly tough performance, especially considering the bottom-rung price for the card.
Keeping things cool while under this kind of load is no easy feat, and thanks to the recently redesigned stock cooler this is pulled off admirably. It's comprised of a chunk of copper that mounts directly over the core, pulling heat away quickly to a series of aluminium fins while three thick heatpipes pitch in at the same time, getting all the 190W-worth of heat out of there as fast as possible. A big squirrel-cage fan at one end pulls in plenty of fresh air, and most of the heat is vented out the back of the case via the PCI slot. In place of the usual anime girl is a Lara Croft clone (subtly tweaked to avoid copyright of course), but otherwise the card is pretty standard to look at.
Power is provided through two identical PCIe 6-pin connectors, while the twin Crossfire nipples at the top allow up to three of these cards to be used in some enthusiast mobos. Two DVI ports round out the expansion options alongside an analogue out, and the cooling fan is powered by a 4-pin PWM cable that gives you total control over speed (and therefore noise and cooling). We measured an idle temp of 54 degrees at 60.1dBA, and a load of 65 degrees at 68.2dBA, which is pretty good considering the heat it has to deal with; just make sure you've got plenty of case airflow to get fresh air to the card.
All this would be rather pointless without performance to back it up, but thankfully this is one area where the card isn't lacking. It returned a stable average 60-ish fps in Crysis, 100 fps in GRID and a buttload of points in both 3DMark programs, which by all measures is more than enough performance for the most demanding of single-core-loving Atomicans out there. We benched the card again at the max overclock we hit, and got a score of 18,202 in 3DMark06.
With a bundled copy of PowerDVD 7 and overclocking prowess to tuck under its belt, the Sapphire 4890 is a very solid choice that's sure to please.
Issue: 107 | December, 2009