ATI Radeon HD 4830

Verdict: [+] BUDGET 1,920 x 1,200 gaming for less than £100; faster than GeForce 9800 GT in most test games and resolutions [-] SPEND FRIVOLOUSLY
Radeon HD 4850’s only cost around £105 now

ATI’s 4800 series has caused Nvidia to have more knee-jerk reactions than an accident victim finding his legs for the first time having been bed-ridden for six months. Nvidia has been releasing a lot of supposedly new cards lately to combat the threat of the Radeon HD 4670 and HD 4850 with GeForce 9600 GSO and 9800 GTX+ cards. Meanwhile the prices of other Nvidia cards have, on occasion, been in emergency decline to combat the HD 4870. Now it’s time for ATI to release a card that seems, on the face of it, completely unnecessary. Enter the Radeon HD 4830, which fits in somewhere between the £60 HD 4670 and the £105-or-so HD 4850 and is aimed squarely at dissuading you from buying a £110 GeForce 9800 GT (which is just an 8800 GT with Hybrid SLI support). SPECIFICATIONS The new HD 4830 is essentially a cut-down HD 4850, with the same 512MB of GDDR3, and a 256-bit memory interface but slower clock speeds and fewer stream processors. The GPU is clocked at 575MHz compared to 625MHz on the HD4850 and the memory runs at 900MHz (1.8GHz effective) as opposed to 993MHz (1.986GHz effective). The HD 4830 has 640 stream processors while the HD 4850 has 800. HOW WE TESTED We benchmarked the HD 4830, HD 4850 and the 9800 GT using Call of Duty 4, Crysis and Race Driver: Grid. We used the BETA Catalyst driver supplied by ATI for the HD 4830, Catalyst 8.10 for the HD 4850 and Forceware 178.24 for the 9800 GT. We also carried out Folding@home and power consumption tests. RESULTS Click here to open the benchmark results graphs (opens in new window) CALL OF DUTY 4 All the cards on test breezed through the tests up to 1,680 x 1,050, with the HD 4850 noticeably faster than the other two cards. Generally the HD 4830 was faster or as fast as the 9800 GT at every resolution. It ran the game at a minimum of 44fps rather than 39fps at 1,280 x 1,024 and both cards achieved a minimum of 33fps at 1,680 x 1,024. The 9800 GT had a higher average frame rate at both of these resolutions, but it’s the minimum frame rate that determines whether a game is stuttery or smooth and so that’s the more important number. Running Cod4at 1,920 x 1,200 makes it a demanding game though we set 4x AA and used maximum AF, all three of these roughly £100 cards managed playable minimum frame rates of above 25fps. The 9800 GT was slowest at this resolution with a minimum frame rate of 26fps with an average frame rate of 41fps. The HD 4830 was just ahead with 27fps minimum and a 42fps average and the HD 4850 comfortably outpaced both with a minimum frame rate of 29fps and an average frame rate of 51fps. CRYSIS Crysis usually brings graphics cards to their knees and unfortunately the HD 4830 struggled at anything above a resolution of 1,024 x 768. Even here it was slower than both the other cards on test with a minimum frame rate of 28fps and average frame rate of 41fps. The 9800 GT and HD 4850 both recorded a minimum frame rate of 33fps and an average frame rate of 44fps – a much more enjoyable experience. The HD 4850 came close to running Crysis smoothly at 1,280 x 1,024 but could only manage a minimum frame rate of 24fps with an average frame rate of 30fps. Again the 9800 GT was slightly slower than the HD 4850, with a minimum frame rate of 22fps and average frame rate of 27fps. Above this resolution, the results were unsurprisingly a washout so you’ll have to opt for something more potent for high-res Crysis gaming. RACE DRIVER: GRID The HD 4830 really comes into its own against the 9800 GT in this game, where it was considerably faster at all resolutions. At 1,920 x 1,200 it recorded a minimum frame rate of 51fps and average frame rate of 64fps while the 9800 GT was well behind with a minimum frame rate of just 39fps and an average frame rate of 50fps. The game was playable on the 9800 GT at 1,920 x 1,200, but the cheaper HD 4830 was faster. The HD 4850 was much faster than the other cards, recording a minimum frame rate of 58fps and average frame rate of 75fps at 1,920 x 1,200. OVERCLOCKING Overclocking the HD 4830 proved to be relatively fruitful although we were unable to raise the speed of the GDDR3 memory above its default speed of 900MHz without corruption. Using AMD GPU clock tool we successfully raised the GPU core speed from 575MHz to 700MHz. This yielded a small improvement in CoD4 at 1,280 x 1,024, boosting the minimum frame rate from 44fps to 48fps and the average frame rate from 67fps to 69fps. A larger gain was seen at 1,920 x 1,200 where it matched the HD 4850 with a minimum frame rate of 29fps and average frame rate of 51fps. It’s possible the inability to raise the GDDR3 clock speed is driver related. However, while a HD 4830 is in all likelihood a HD 4850 with disabled stream processor clusters, ATI confirmed that these stream processors are disabled in hardware, so a VBIOS flash won’t re-enable them. FOLDING With Custom PC now residing in the number 5 spot at Folding@home, largely thanks to our team members getting their graphics cards in on the act, we also obtained PPD and power usage results for all three cards. Unsurprisingly, the 9800 GT was well ahead of the two ATI graphics cards, recording an impressive 5,057ppd from project p4742 with the system drawing just 272W. The HD 4850 recorded 2,940ppd from the same project with the system drawing 326W while the HD 4830 generated 2,545ppd again from project p4742 with the system drawing 289W. The 9800 GT is still the best choice for avid folders. POWER CONSUMPTION We used the Canyon Flight test in 3DMark06 to ascertain the maximum power draw figures for our test system with each card installed. With the 9800 GT the test system drew 318W, using the HD 4830 it drew 299W and with the HD4850 it drew 339W. That the HD 4830 consumes less power than the 9800 GT is surprising given that it’s faster in two of our three test games. CONCLUSION There’s clearly a gap in the market that ATI feels should be filled and the HD 4830 has the performance and value to fill it. However, we can’t quite see where this gap is. The HD 4850 has the 9800 GT licked for performance and costs a little bit less. The HD 4830 might cost less still and still outperform the 9800 GT, but we’d still spend the little extra and invest in a HD 4850. If you have no more than £100 to spend, then the HD 4830 is a good buy, however, and if you can hunt one out for less than our estimated price of £90 inc VAT then even more so. Just remember that if you stumble across a HD 4850 for £100 when bargain hunting on the web, that’s the card to go for.For more information on the Radeon HD 4830, visit ATI's websiteTo buy a Radeon HD 4830, see our Where to Buy news story here**UPDATE: Nvidia reminds us that PhysX and CUDA apps such as BaDaBoom will only run on moden GeForce cards such as the 9800 GT**