ATI Radeon HD 4830 Performance Preview
Since successfully launching their RV770 family of Radeon 4850/4870 cards earlier this summer, ATI has been slowly filling in gaps in their overall product lineup. At the ultra high-end of the GPU market ATI has their flagship Radeon 4870 X2, a graphics card which is universally acknowledged to be the fastest in the world. As its name implies, the 4870 X2 fuses two Radeon 4870 1GB GPUs together onto one card and is priced in the $500+ range.
On the opposite end of the graphics spectrum is the Radeon 4670. This card features just 320 shaders (less than half that in a Radeon 4870) and a narrower 128-bit memory interface, but with its sub-$80 price tag it delivers very good 3D graphics performance for the money as long as you’re willing to compromise a little on the graphics settings (4xAA is doable in most games as long as you’re willing to turn down some of the game’s graphics settings).
Finally, two weeks ago ATI introduced the sub-$60 Radeon 4550 for the entry level segment.
Despite the recent flurry of Radeon graphics launches, one graphics segment ATI has missed is the $100-$140 market. Here ATI’s been forced to rely on their older Radeon 3850 and 3870 cards. These cards are nearly a year old now and have historically had a tough time competing with NVIDIA’s highly popular GeForce 8800 GT, which is priced in the same $100-$130 price range (keep in mind that NVIDIA has recently renamed the 8800 GT to the 9800 GT).
To counter the GeForce 8800 GT/9800 GT, ATI has finally concocted a GPU sourced from their RV770 architecture, the RV770LE GPU.
Packing 740 GigaFLOPs of processing power, RV770LE is essentially a watered-down version of RV770: ATI simply takes the same RV770 chip already used in the Radeon 4850, lowers the clock speeds, and disables two SIMD cores (ultimately disabling 160 stream processing cores), leaving 640 active shaders. The final product is then named the Radeon 4830.
The following chart summarizes the key features of the various Radeon 4800 SKUs:
|Radeon 4800 Series Comparison|
|Radeon HD 4830||Radeon HD 4850||Radeon HD 4870|
|Core Clock Speed||575MHz||625MHz||750MHz|
|Memory||512MB GDDR3||512MB GDDR3, 1GB GDDR3||512MB GDDR5, 1GB GDDR5|
|Memory Clock Speed||1.8GHz Effective||2.0GHz Effective||3.6GHz Effective|
|# of Stream Processors||640||800||800|
|Compute Power||740 GFLOPs||1.0 TFLOPs||1.2 TFLOPs|
|Max Board Power||110W||110W||160W|
While we listed the price of the Radeon 4830 at $129 in the table above, we’ve been told that street prices will likely be lower thanks to mail-in rebates. We weren’t given a firm figure for how significant these rebates could be or when they’ll even take place, so you may want to wait a few days to see how low final street prices ultimately are.
Same 4850 board design
The Radeon 4830 uses the exact same board design and single-slot cooling as its bigger brother, the Radeon 4850. Physically the reference board design of the 4830 is 100% identical to the Radeon 4850. This makes life easier for ATI’s board partners, who can simply recycle their 4850 designs for the cheaper 4830.
As you probably know by now ATI has been criticized for the performance of its 4850 cooler – the card runs very hot even under idle – but the company has recently addressed the temperature issue by adding the option to manually adjust the fan’s RPMs in the Overdrive section of the driver control panel in Catalyst 8.10. If you’re unhappy with the temperature of your 4800 series card (including the 4830) and would like it to run a little cooler, simply unlock Overdrive and use the fan control slider to increase the fan’s RPMs. Your card will run a little louder as a result, but it’s better than nothing.
Fortunately thanks to its reduced shader count and slower clocks, the Radeon 4830 runs significantly cooler than the 4850. As you’ll see in our benchmarks, the idle and load temps between the two cards are drastically different even though they rely on the same basic board design and cooling.