Three Radeon HD5670s compared benchmarked

Having assaulted the ultra high end (HD5970), high end (HD5870, HD5850) and the mainstream (5750 & 5770) market segments with its new 40nm DX11 architecture HD5**** series of card the firm has now turned their attention to the real bread-and-butter part of the market, namely the value end, hence the Radeon HD5670.

The HD5670 (codename Redwood or to be more precise Redwood XT) is a cut-down version of the HD5770, itself a cut down version of the mighty HD5870. With the HD5670 the transistor count drops below a billion(s) for the first time in the family to 627 million with the cut-down core measuring just 104mm².

The stream processor count is halved from the HD5770 (400 down from 800) with the texture and ROPs also halved as well; 20 and 8 respectively. The shader and core clock run at 775MHz. One thing that hasn’t been touched is the memory interface which remains at 128-bit. At the moment there are two flavours of the HD5670 with 512MB and 1GB of GDDR5 memory, clocked at 1GHz (4GHz effective) which gives a memory bandwidth of 64GB/s, very impressive for a card in this part of the market.

The reference design PCBs use Hynix H5GQ1H24AFR-T0C chips which are rated at 4GHz so there isn’t much headroom for overclocking. The added benefit of the smaller die size is that the card doesn’t need any more power to run other than the 75 Watts supplied by the PCI-E slot, as its maximum wattage is just 61 Watts (14Watts idle). So there’s no extra power connector on the cards PCB, which is handy as the card's single slot design, the first DX11 single slot card, measures 169mm x 110mm x 33mm (WxDxH) meaning that it should be able to fit into smaller systems.

Despite the cut-down nature of the architecture it retains the feature set of the rest of the 5000 series, amongst which are: DirectX 11 support, UVD2 video decoding, HDMI bit streaming and even support for the three-monitor Eyefinity technology.

Surprisingly, how Crossfire is implement is left largely down to the board vendors, in the case of our review boards the reference design had no connectors while the Sapphire board had the usual dual connectors.

So much for the reference design.

See page 2 for a look at how Sapphire's 1GB version of the HD5670 compares to that from HIS, which sports the standard 512MB of graphics memory.

Sapphire Radeon HD5670 1GB
Price £90.61

Sapphire’s HD5670 1GB has the memory and core clocks set at the reference design speeds (775MHz core, 1GHz (4GHz effective) memory) but using Hynix H5GQ1H24AFR-T2C memory chips which are rated at a maximum data rate of 5GHz so there’s some overhead if you want try and overclock.

What has changed is the cooler design, Sapphire choosing a larger Arctic Cooling designed cooler with a direct airflow fan, all of which changes it from the single slot solution of the reference design to a dual slot card and cools the card in near silence.

As on the reference design, on the endplate you will find a dual-link DVI port, a DisplayPort and a HDMI port, and there’s a HDMI-DVI adaptor in the box so you can connect this port up to another DVI ported monitor.

Although it might not look much like the reference design, under the skin Sapphire Radeon HD5670 1GB version of the HD5670 has reference clocks all the way.

HIS HD5670 IceQ 512MB
Price TF

As this is a member of the IceQ family, the card is dominated by the large but very effective, quiet Arctic Cooling heatsink that makes this family line-up of cards stand out from the rest, and like Sapphire’s card turns it from a single-slot solution to a dual-slot one.

The backplane differs from the reference design by having a standard VGA port in place of the Displayport but keeps the DVI and HDMI ports, which for a card in this lower end part of the market makes a lot of sense.

Unlike Sapphire’s card, HIS’s HD5670 doesn’t have the dual Crossfire connectors on the top of the card, but it still supports Crossfire, sending the data across the PCI-E bus instead.

Benchmarks and our verdict, page 3.


Click image to see full size


As the results show, there isn’t much to choose between the 1GB and 512MB flavours of the HD5670, and therein lies the problem.

Currently there is around £20 difference between the two cards and with the 1GB cards costing around £90 they are getting perilously close to the previous generation HD4850 and Nvidia’s 9800GT cards, both of which are much better gaming cards if you can live without all the new feature of the HD5**** series.

If the price of the 1GB cards settles downwards, and the market will probably make sure it does, it will be the one to go for, not for the performance it offers but for the wider selection of ports that partners will tend to offer on the higher speced cards.

It also is an ideal upgrade if you don’t want to go through the hassle of buying and installing a new power supply as it doesn’t need any more power than the PCI-E slot provides.

When you sit and think about AMD are offering to the value end of the market; GDDR5, DX11, Eyefinity, bitstreaming audio etc and a good degree of future proofing it really is amazing. It’s not really a gaming card but it does offer plenty for the HTPC (Home Theatre PC) builder.