However, the 'RV790' chip design that's the basis for the 4890 is rather more than a simple speed bump of the 'RV770' used in the 4870. For starters, it's bigger and measures some 16.5 x 16.5mm rather than 16 x 16mm, which is an increase of about six percent in area. The fabrication process of both chips is 55nm, and the number of transistors is also the same: 956 million. So we’re talking about a reorganisation of the chip rather than a redesign.
CPU-Z: Radeon HD 4890 (left) and 4870
Click each pic for a full-size image
Running the new graphics chip at such high clock speeds requires plenty of electrical power so the RV770 has been designed to work with a graphics card that can supply five-phase voltage regulation. The result is that 4870 has an idle power draw of 90W and a maximum power draw of 160W. The figures for 4890 are 60W and 190W, so the new graphics card should draw less power at idle and more power under load.
You can buy an 4870 with either 512MB or 1GB of memory, but the 4890 is only available with 1GB. We 're not exactly comparing like-with-like here, as our Asus EAH4870 had 512MB of video Ram while the EAH4890 has 1GB. We were careful to avoid extreme anti-aliasing settings that would favour the the larger frame buffer, so we're confident that our test results accurately reflect the differences between 4870 and 4890.
Unfortunately, there is no way to make an allowance for the power draw of the extra 512MB of memory so all we can say is that our figures show the overclocked 4870 draws 5W more than the 4890 at idle and 10W less under load.
Lay a 4870 next to a 4890 and we defy you to tell the two cards apart:
Asus' 4890 (top) and 4870
We tested the graphics cards on a Gigabyte MA790FXT-UD5P motherboard with a Phenom II X4 810 that we overclocked from 2.6GHz to 3.25GHz, 2GB of Kingston DDR 3, an 80GB Intel X25-M solid-state drive and Windows Vista Ultimate. We had planned to use Catalyst 9.3 drivers but they didn’t recognise the 4890 so we used the drivers from the Asus 4890 with both cards - let’s think of them as Catalyst 9.4 Beta.
COMMENTS
ATI card in my vista PC
Biggest hardware upgrade mistake I've ever made.
With catalyst installed, aero randomly crashes.
With catalyst uninstalled, I get other errors like black squares showing up occasionally around the cursor, video upscaling not rendering properly and my dual monitors not staying in place after a restart.
So, current solution is "Windows Classic" theme, which is kind of annoying, since I do actually like the look of aero, and the PC and card is fast enough to run it.
Vista and by extension, this driver problem, has been around for what, nearly 4 years now? And windows 7 also has aero, so the problem won't be going away anytime soon. The excuse of "it's Microsofts problem" is starting to wear a little thin.
@ Dave
Dell isn't in the business of selling PSU at retail, and tests true PSU capacity from it's suppliers. Therefore, what you're getting with a Dell PSU rated for 350W tends to be one that's actually capable of it, and the whole integrated system also tested to be lower consumption which makes sense as you wouldn't expect a quad core box with a 3650 in it to reach 275W peak, let alone 350W.
Typical power requirements cited by video card manufacturers are to shift the burden and expense of instable equipment to the owner, how easily they can tell someone to throw more money at a problem because there are so many PSU out there that don't live up to their ratings.
On the other hand, a modern system with a 4870 or 90 video card in it ought to have higher than 350W PSU powering it, but if/when the day comes that Dell integrated (term loosely used, not meaning soldered onto the mainboard) these 4890 into systems they will provide a beefy enough PSU to at least handle the one installed card even if it cannot support Crossfire.
@AC: Academic
I bought 2 Dell home machines with ATi 3650 cards (1 for dad, the other for a friend), BOTH had incorrectly installed ATI drivers that caused errors and crashes.
The problem is the piss-poor way that Dell install them, not necessarily the hardware. The thing to try is a complete un-install of the Dell supplied drivers. Then use DriverCleaner or similar to ensure that all the registry keys have been removed as well. Then restart, and then install a new fresh, Catalyst from ATI. Do NOT use Windows Update or a Dell driver. That should clear up the issues - well fingers crossed! It did for those two machines mentioned above.
If not, then Dell has this annoying tendency to use PSUs that are severely under-powered for the hardware (my Dell Studio not XPS is a quad core, 8GB ram with ATi 3650 and had a pathetic 350W PSU). Try changing the PSU to a 500W min, decent quality PSU. Should help no end or see here: http://ati.amd.com/products/radeonhd4800/requirements.html for power requirements for the HD4800 series.
4830 for todays budget concious
£300 on a gfx card is madness! I paid £70 for my 4830 (quidco for teh win) and it might not be the fastest kid on the block but will play happily in 1680x
I suppose I could Xfire it if I had a mobo but why bother - the mobo would cost just as much...
Telling them apart...
Apart from the obvious pictures on the heatsink/exhaust thing, the two silver things on the end of the cards(capacitors?) are different sizes on each card. Defy that!! :-)
