ATI Radeon HD 3450, HD 3470 & HD 3650 graphics cards

Radeon HD 3450/3470/3650 unveiled

So what's new with the lower-end Radeon HD 3000-series GPUs, then?

It's table time and then an explanation. Taking the Radeon HD 3650 first.

AMD Radeon HD 3650 series

* Derived by adding a MUL to the MADD.

Nomenclature

The underlying architecture is similar to the upper echelons of the Radeon HD 2000-series, which we took a look at here. So just as the Radeon HD 3800-series incrementally improved upon the Radeon 2900 XT that was launched eight months previously, the Radeon HD 3650 does the same when compared against the HD 2600 in its various guises.

Taking it from the top, as per the models higher up in the 3K range, the HD 3650 doesn't ship with Pro or XT suffixes. Rather, the two models in the range are both referred to as Radeon HD 3650, and the user will need to determine whether the main differentiating factors - memory speed (GDDR3 or DDR 2) and size (256MiB or 512MiB) - are present on the card of their choice. It's these factors, and these factors alone, that define the actual Radeon HD 3650 sold by add-in board partners.

HD 3000-series benefits - DX10.1; PCIe 2.0; 55nm production; wider choice of display options; PowerPlay

Being a 3000-series GPU, the HD 3650 benefits from a slew of GPU-based upgrades when compared to the incumbent Radeon HD 2600 series. The transistor count remains around the same, at just under 400M, but the smaller manufacturing process leads to, well, a smaller GPU and, consequently, lower production costs for ATI.

DX10.1 is an incremental upgrade to the Vista-specific API but it will take time before developers code for it, so we don't see this is a must-have feature right now. Another 3K feature, PCI-Express 2.0, will be useful for GPUs that are equipped with, say, a 256MiB framebuffer, where constant access to slower system memory, traversing the PCIe bus, is more frequent. Again, though, it's incremental rather than revolutionary.

The Radeon HD 2600-series of GPUs are reasonably frugal when evaluated in power-consumption terms. ATI's refined the process with the double-whammy of a more power-efficient manufacturing process and PowerPlay, where the GPU's transistors are intelligently gated depending upon load, such that it draws considerably less power when idling or subject to light gaming. Again, this is a carry-over from the Radeon HD 3800-series.

What's all-new here is the provision for DisplayPort connectivity - a competitor to HDMI. DisplayPort can drive a 30in panel at its native resolution - 2,560x1,600 - from a single cable, and supports DPCP (DisplayPort Content Protection, 128-bit AES) as well as HDCP compliance, too. It doesn't require separate control logic on the panel side, either, and backwardly supports HDMI passthrough. Whilst the controllers are integrated into the GPU, actual DisplayPort connectivity will be added on a per-SKU basis. Right now, only a handful of panels support the standard, and its popularity will grow as the nascent technology takes off and is widely implemented.

The guts are still the same, though

The non-3D benefits are clear to see, on paper at least, but the 3D capabilities are pretty much the same as the HD 2600 series. 8 texturing units and a 725MHz core and shader speed - down from the 800MHz present on the HD 2600 XT, by the way - gives the HD 3650 a 2.9GT/s fillrate. That's some way below NVIDIA's GeForce 8600 GT, and the HD 3650 will suffer in pixel-pushing and texturing scenarios, comparatively speaking.

The range-topping 2600 XT's GDDR4 has been dropped in favour of cheaper GDDR3, thereby keeping costs down. Given the same 128-bit memory-bus width, there's a bandwidth deficit as a result, although minor core improvements will help mask some of the shortcomings.

Think of the Radeon HD 3650 as a Radeon HD 2600 XT GDDR3, albeit with a bunch of minor updates. Pricing is keen, too, with the DDR2 model retailing for around £45 and the faster GDDR3-equipped SKU for around £59, including VAT.

We expect to see passive designs from the usual band of AIBs in due course. NVIDIA is busying readying its response with a 9-series update to its midrange SKUs, so the above table will change again in due course.

Radeon HD 3470 and HD 3450

Let's now skip to the Radeon HD 3450/3470 now.

The Radeon HD 3400-series is split into two separate SKUs. This time, the HD 3470 has a higher core and shader speed and, by ATI's thinking, deserves a higher nomenclature than the HD 3450. Again, what the HD 3650 adds on to the HD 2600's specification is generally mirrored here, too - we have the DX10.1 spec; PCIe 2.0; 55nm fabrication; DisplayPort connectivity; PowerPlay, etc.

The low-end HD 3000-series cards are clocked in, core-wise, faster than the two models they will inevitably replace. The GDDR3 model, in particular, also ships with faster memory, operating at 1,900MHz. Pricing, though, will be around the same.

We expect to see manufacturers opt for passively-cooled and half-height models, especially with the HD 3450 SKU. Its enviable list of connectivity options and low street price will make it attractive for buyers looking for their next HTPC card.

The new GPUs support ATI's CrossFireX multi-GPU technology, albeit 'limited' to two cards.

Summary

No real surprises with the introduction of three distinctly new SKUs that bolster the Radeon HD 3000-series line-up. ATI's updates to its low-end GPUs take in much of what was new in the HD 3850/3870 range and add better display options to boot. With the introduction of these new SKUs, then, there's no compelling reason to look at HD 2400/2600 cards now, other than, perhaps, a sharp drop in price. The HD 3450/70/3650 are cheaper to produce, offer similar 3D performance, yet are more future-proof than the current range. We await to see NVIDIA's refresh for its range of sub-£50 (retail) GPUs with bated breath.