Today we remind ourselves of why Radeon HD 4870 cards are as popular as they are in the gaming community. Our weapon of choice is 4870 IceQ 4+ Turbo graphics card kindly provided by HIS.

We see that the card's name contains IceQ 4+, which means that the card comes with this famous HIS's cooler. In our book, IceQ spells great cooling that we've grown to love, but IceQ 4+ is a new and improved version, and we'll soon find out how improved exactly.



As far as memory is concerned, HIS HD 4870 IceQ 4+ is a beast. You’ll find 1GB of GDDR5 memory running at 1000MHz or 4000MHz effectively. These cards initially packed 512MB, but 1GB versions came about as an answer to Nvidia’s Geforce GTX 260 cards.

The additional memory wasn’t so important until DirectX 10 came around, but newer games coupled with high monitor resolutions have a tendency to eat up graphics cards’ frame buffers, and it’s exactly those scenarios where we see 1GB cards dominating the 512MB versions. We of course, don’t expect you to take just our word for it, and we’ll soon prove our claims with our extensive testing.

GDDR5 memory offers twice the bandwidth per pin at same clocks, compared to GDDR3/4 memory. This means that 512-bit GDDR3 card features the same bandwidth as 256-bit GDDR5 cards, provided they’re both running at same clocks of course. While HD 4870 uses GDDR5 memory at 900MHz and has a 115.2GB/s bandwidth, Radeon HD 4850’s GDDR3 memory at 993MHz will provide 63.6GB/s. 

Both aforementioned HD 4800 cards use a 256-bit memory bus, but thanks to HD 4870’s GDDR5 memory, this card holds its own nicely even when put up against the GTX 260, which features a 448-bit memory bus. The GTX 280 features a 512-bit memory bus and a bandwidth of 141GB/s, whereas GTX 260’s bandwidth totals at 111.9GB/s. HIS card’s memory is overclocked to 1000MHz and it scores a bandwidth of 128GB/s.



Now we’ll say something about HIS HD 4870 IceQ4+ Turbo’s overclocked core, which runas at 770MHz compared to reference 750MHz. Although IceQ 4+ packs some serious performance, HIS didn’t overclock the card by much. After we finished our overclocking tests, it dawned on us as to why this is so, as the maximum stable clock we achieved was 808MHz. HIS was fair and didn’t go overboard with their overclocking. However, even at 770MHz and the memory at 1000MHz (4000MHz effectively) this card is capable of running all the latest games.

Radeon HD 4870 uses the RV770 graphics processor, built in 55nm process. It has 800 shader processors at its disposal, which is 2.5x more than found in previous, HD 3800 generation. The same goes for texture units as the card has 40 (HD 3800 had only 16). You can find the rest of the important specs on the GPUZ picture below.



HIS card’s dual slot cooling is more efficient that reference, but we must admit that we expected it to be quieter. The fan won’t be as loud if you manually slow it down; otherwise the speed is dynamically altered and gets quite loud. Unfortunately, this is not only the case when the card is under a workload, as the card is louder than the reference version in idle mode too. On the other hand, HIS card runs 25°C cooler than reference, which although nice, we’d still sacrifice a couple of degrees in order to enjoy the silence. As we’ve already said, regulating the fan’s rpm can be done manually without any problems whatsoever.



ATI Catalyst Control Center features an integrated overclocking tool called Overdrive, but you can use it to control the fan as well. That is the central point where you’ll be able to check the graphics card’s temperatures or increase the clocks. Unfortunately, Overdrive will let you increase the core to a maximum of 790MHz – 40MHz higher than reference, whereas RivaTuner will let you overclock even higher.

We increased the clocks using the Overdrive tool, and we had no trouble in reaching the maximum allowed 790MHz core and 1100MHz memory, but using RivaTuner allowed us speeds of up to 808MHz. In order to protect the core, each time we’d set higher clocks, the engine would revert the clocks to default 770MHz.



In HIS’s predefined operation mode, the fan in idle mode runs at 39% speed, about 2300 rpm. This is a powerful fan with UV color (the card glows blue when exposed to UV rays) capable of running at maximum 5700 rpm. We tried to make it inaudible, which required the fan to run at 33% speed, 1688 rpm. Note that maximum of 5700 rpm in idle mode will rapidly lower temperatures to below 40 degrees Celsius.

We measured the following temperatures (leaving the fan at HIS default settings): during operation the temperatures hit up to 63 °C (reference card up to 89°C), but the card ran too loud for us. Idle temperatures linger around 49°C, but you can sacrifice the temperatures to get some silence, which we achieved by lowering the rpm to 33% and temperatures hit 55 degrees. The quieter fan results in workload temperatures of 80°C, but we still preferred it over the loud operation with temperatures at 63°C.

The cooler does a good job and pushes the air out of the case, thus keeping other components cooler. The fan is located at the back and blows trough the aluminum heatsink towards the exit, which is the I/O panel of the card.



The new IceQ4+ cooler features a larger copper surface than found on previous models, and we see that the memory touches the cooler as well. The efficiency was improved by using wider heatpipes, which are now 8mm in diameter, compared to the previous 6mm.



HIS used the same memory seen on reference cards. HD 4870 IceQ 4+ Turbo features a 1GB/256-bit high-speed GDDR5 memory, which touches the cooler. The memory in question is Qimonda IDGV1G-05A1F1C-40X, where 40X stands for 4.0 Gbps per pin.



Powering the HD4870 card is done via two 6-pin PCI-Express power connectors located towards the end of the card.



The back of the card is not nearly as interesting, but here it is.



All the HD 4xxx cards provide 7.1 sound, thanks to Realtek’s HD Audio processor integrated into the GPU silicone. There’s no need for additional cables when you want to bring both audio and video via one HDMI cable, which is the case with Geforce cards. HDMI is possible using the provided DVI-to-HDMI dongle. The outs feature two gold-plated dual-link DVI outs and an S-Video out.



HD 4870 IceQ 4+ Turbo comes in small but sturdy packaging. You’ll find some basic info written on the box, such as the 770MHz clock.



The box contains basic stuff - nothing else.



You’ll get a DVI-to-HDMI converter, DVI-to-VGA converter, Molex-to-PCI-E cable, Crossfire Bridge, a short installation manual, a HIS sticker, the driver CD and the graphics card.