HIS Radeon HD6670 iSilence 4 review

Silent and capable graphics card, just don’t use it for gaming
Photo of HIS Radeon HD6670 iSilence 4

As you might be able to glean from the name, the Radeon HD6670 iSilence4 from HIS is the latest in a long line of passively cooled and therefore silent graphic cards, from the Hong Kong based company. 

This latest member of the iSilence family is based around AMD’s HD6670 (codename Turks) 40nm core – which is one of the best performing lower-end, of the mainstream market segment graphics cores.  HIS have kept to AMD reference design for the core clock speed, namely 800MHz, the same speed at which the 480 Stream processors run.

Silence is golden

To keep the HD6670 iSilence 4 cool, HIS have turned to one of the masters of the cooling art, Zalman, to provide the passive cooling technology for the card. Unlike most of their competitors who have quite bulky coolers on their passive design’s, the Zalman cooler is a much more compact design. This uses three slim-line heat pipes, which join the top multi-finned cooler on the heatsink, sitting on top of the GPU.

It’s only when you look at the memory specification’s for the card that you can see why HIS have been able to use such a slim design. Instead of the GDDR5 memory of the reference HD6670 design, as most of their competitors do, HIS have used 1GB of DDR3 clocked at 1600MHz – which runs a lot cooler. 

Not one for gaming

Unfortunately, the downside of the choice of memory is a hit on the card’s performance. Today’s passive cards can almost keep up with their actively cooled cousins in performance, but the iSilence4 is a nod back to a previous generation when passive cards were the poor relations, when it came to performance. For example, a standard HD6670 gives a frame rate of 25fps when tested with DiRT3 at a 1080p resolution, while the iSilence4 manages just 13fps.

Compact and capable

On the other hand, the iSilence 4 is slim enough (204 x 127 x 38mm HxWxD), to fit into quite compact HTPC cases. This is something that can be almost impossible to do, with some of the cards with a more bulkier cooling solution. In this instance, the hardware features of the HD6670’s architecture come into play, such as AMD’s HD3D technology, integrated HD audio controller, HDMI 1.4a support and its UVD 3 dedicated video playback accelerator. The card also gets all the power it needs from the motherboard, without the need to use a separate feed from the power supply.

Company: HIS

Website: http://www.hisdigital.com/gb

  • Totally silent operation and no extra power requirements.
  • Lacks the performance of other passive and standard cooled HD6670 cards.


What the iSilence 4 loses in performance it makes up for being a compact silent card. It’s ideal if you putting together a small format HTPC or a silent PC, where gaming performance isn’t a requirement.