Board analysis

If you believe ATI’s marketing materials, the 5970 is an “unlocked” graphics card with “massive” overclocking headroom. In fact, in during our discussion with ATI officials, the word “overbuilt” came up more than once. The way ATI sees it, the card is overbuilt for the 5850 speeds it runs at, and is basically a 5870 lurking in disguise just waiting to be unlocked.

But is it really overbuilt? Let’s see.

ATI says that the RV870 GPUs inside each Radeon 5970 are cherry-picked Cypress XT chips. In case you don’t know, Cypress XT chips are the same ones used in the Radeon 5870 – the 5850 relies on less capable Cypress Pro chips.

The Cypress XT chips used inside the Radeon 5970 are specially sorted at the factory for low leakage. They run at lower voltage than the Cypress XT chips used in regular Radeon 5870 cards and generate less heat.

In other words, they’re the very best chips ATI has to offer.

But it doesn’t stop there. ATI also employs a vapor chamber cooler that they say is rated to handle up to 400W. In stock form, the Radeon 5970 tops out at just 294W, so the stock 5970 cooling is more than capable of dissipating this heat, with room for much more.

The vapor chamber cooler ATI employs is a custom design made in-house by ATI. ATI says that their cooler is not based on Sapphire’s vapor chamber technology, which is sourced from a Taiwanese company named Microloops and was recently hit with a patent infringement suit from a company based here in the US, Convergence Technologies.


The vapor chamber cooler is made completely from copper and is cooled by a dual-slot aluminum heatsink with large rolled fins. An aluminum base plate is then placed on the underside of the card to help dissipate heat off the bottom of the PCB, as well as provide an additional form of protection for the GDDR5 memory modules located on the bottom of the card from being accidentally damaged during shipping.

Like the Radeon 5870, the length of the Radeon 5970 actually helps boost its cooling performance. Heat from the GPU is dispersed along a plate that’s 10” in length. The plastic duct itself is 12” long and has a full-size exhaust vent out back. The Radeon 5870’s exhaust vent is half as large in comparison.

Size comparison: 5850 (bottom) 5870 (middle) and 5970 (top)

Because ATI uses a full-sized exhaust vent, the 5970 board isn’t outfitted with dual DVIs, HDMI, and DisplayPort like the Radeon 5870. Instead the 5970 drops the HDMI output, opting instead for two dual-link DVIs and one mini-DisplayPort output. ATI says this configuration was chosen for max compatibility: DVI-to-VGA and DVI-to-HDMI adapters can easily be found at affordable prices if they aren’t bundled directly with the 5970 graphics card itself.

Like the 5850 and 5870, digital programmable voltage regulators sourced from Volterra are used on the 5970, and the same Samsung K4G10325FE-HC04 GDDR5 memory modules are used on the 5970. These modules are rated for speeds up to 5Gbps (1250MHz), while the power phases are designed to supply up to 375W of juice to the GPUs.

New Overdrive limits

To further aid your overclocking endeavors, the Radeon 5970 supports much higher Overdrive limits out-of-the-box than ATI’s Radeon 5800 cards do. While the 5870 and 5850 can’t be OC’ed more than 10% using Overdrive, the Overdrive sliders for the 5970 max out at speeds of 1GHz core and 1500MHz memory! The 5870 is capped by default to speeds no higher than 900MHz core/1300MHz memory in Overdrive.

In addition to offering higher limits in Overdrive for the 5970, ATI will also be providing a special voltage tweak tool to their add-in board partners. This tool can be used to up the GPU and memory voltages. All board partners are free to bundle it with their retail 5970 cards if they wish.

Now before you get excited, this tool isn’t nearly as advanced as what ASUS and MSI provide with their latest Radeon cards; only one voltage setting is provided for upping the graphics core and memory voltages, and it doesn’t even save your settings permanently, so you’ll have to dial the voltages in every time you start up your system, but it’s better than nothing.

Stock 5970 voltage

Max voltage setting

The overvoltage tool is a very small utility you run in addition to Overdrive. Simply flip the slider for the graphics core and memory voltages, and you’re all done.

Radeon 5970 Eyefinity support

Right now ATI Eyefinity support with multiple displays is officially limited to single-GPU configs only. CrossFire doesn’t work just yet.

As an added bonus for Radeon 5970 users however, ATI is providing very limited Eyefinity support to the 5970 only. The 8.663.1 driver contains beta Eyefinity support for over a dozen different titles:

Anno 1404 (aka Dawn of Discovery)
Batman: Arkham Asylum
BattleForge
Call of Duty 4 – Modern Warfare
Call of Duty 5 – World at War
Call of Juarez: Bound in Blood
Crysis
Crysis Warhead
Dawn of War 2 (Warhammer 40K)
Elder Scrolls IV: Oblivion
Enemy Territory – Quake Wars
Fallout 3
Far Cry 2
GhostBusters
Left 4 Dead
Need for Speed: Shift
RaceDriver: GRID
STALKER Clear Sky
Tom Clancy’s HAWX
Unreal Tournament 3
World of Warcraft (plus expansions)

Now the Eyefinity support does come with a number of caveats. For starters, support is limited to the games listed above only. No other games are supported yet at this time. In addition, only landscape configurations scale properly. Running portrait mode will still function, but will rely on the primary GPU only. And again, Eyefinity support is limited to the 5970 card at this time.

ATI’s working on rolling out CrossFire Eyefinity support to more GPUs and games, but we probably won’t see anything until late Q4/early Q1 timeframe.

What about the Radeon 5950?

If you’ve been following the rumors for the past few months, you’ve no doubt seen photos of the prototype 5970 board and a second mysterious dual GPU card outfitted with two Orb-style coolers. A photo of this board can be found here.

All along it’s been believed that this second board was a 5850 X2 prototype board. It turns out however that this isn’t the case. ATI says this was a stolen early Hemlock board used during the card’s bring-up phase of development. Everything on that prototype board is completely different than the components used on the 5970 boards launching today. The sample wasn’t even fully functional.

Honestly considering the supply constraints ATI is facing right now, it really wouldn’t make any sense to introduce a Radeon 5950 at this point anyway. As it stands now, ATI’s already using premium Cypress XT chips that could be going into $400 Radeon 5870 cards into the 5970 instead.