Radeon HD 4850/4870 Graphics Cards

We introduced you to the Radeon HD 4850 last week, but we’ll go over the 4850 again before proceeding on to the 4870. The Radeon HD 4850 and 4870 cards we received come from VisionTek. The cards are carbon copies of ATI’s reference design for the 4850 and 4870 GPUs; in fact all board partners are sticking to the reference design for their 1st-generation boards. A few manufacturers have announced enhanced Radeon 4850 cards with features such as dual-slot cooling and 1GB of memory, but none of these boards have made it to market, and they won’t hit retail shelves until sometime next month. With that out of the way, let’s take a closer look at the cards…

VisionTek Radeon HD 4850

The Radeon HD 4850 is a single-slot graphics card with a single 6-pin PCIe power connector and copper cooling. According to ATI, peak power draw of the board is just 110W.

As we mentioned last week, the PCB of the 4850 board gets quite hot under load. In fact even at idle the PCB gets pretty toasty. Unfortunately, ATI does not employ heatpipes with this board, relying instead on just a copper heatsink that reminds us of the cooler used previously on the Radeon HD 3850 (although it’s not the same cooler).

Supplying the heatsink with cool air is a variable spin fan that appears to spin up based on usage rather than temperature, or at least it remains at the same speeds at idle regardless of the actual GPU temperature. A lot of end users have complained about this, as idle temps of 70 degrees (or more) have been spotted with the fan barely breaking a sweat to compensate. Since the fan doesn’t spin up, the temps seem to progressively get hotter in PC cases that don’t have adequate ventilation. Since ATI doesn’t provide a method to adjust fan RPMs manually via slider, you’ll probably want to download a 3rd party app like RivaTuner (once it supports RV770) to manually adjust RPMs to something you’re comfortable with. It’s also possible that ATI could address this issue at some point with a future driver update that adjusts RPMs more aggressively.


We think the ideal solution would be for ATI to incorporate a larger fan, much like many of NVIDIA’s board partners did last year when the same problem surfaced on the GeForce 8800 GT. That single-slot board also quickly developed a reputation for running hot until a larger fan was integrated onto the card. Spinning at the same RPMs as the previous fan, this new design dramatically reduced temps without generating a lot of noise, effectively addressing one of the 8800 GT’s few shortcomings.

VisionTek Radeon HD 4870

With its higher clock speeds and power draw (up to 160W), ATI has come up with a dual-slot cooler for the Radeon HD 4870, and the card requires two 6-pin PCIe connectors for power. At 9.7”, the Radeon HD 4870 also measures slightly longer than the Radeon HD 4850, but it’s still nowhere near as long as a GeForce 9800 GTX or GTX 260/280.

In terms of cooling, ATI has developed a cooling system with two copper heatpipes and an aluminum heatsink cooling the heatpipes. A red metal plate is also used to help dissipate heat off the top of the PCB.

ATI borrows the same fan originally used on the 3870 X2 for the Radeon HD 4870. It’s a variable speed fan that runs near silently at idle, and even under load is still under 50dB. Like other dual-slot cards, the fan exhausts hot air from the GPU outside your case, helping to keep the inside of your system cool. Unfortunately though, like the Radeon HD 4850, the 4870’s PCB gets quite hot under use.


Officially Radeon HD 4870 cards will go on sale beginning today, but we’ve been told that supplies of GDDR5 memory have been holding things up and that you won’t see cards en masse until next month. So if you do happen to see a 4870 card in stock today and you want to buy it, don’t wait as retailers may have a hard time keeping boards on hand.

We should also note that while both VisionTek cards carry Mass Effect PC logos and branding (both on the box and on the cards themselves), neither of our boards actually shipped with a copy of the game itself.