Sapphire gives its new flagship graphics card 6 GB of very fast memory, compared to the mere 3 GB on AMD's reference card. Does this give Sapphire's Toxic HD 7970 GHz Edition a real-world speed boost? We connect it to an epic six-screen array to find out.
Sapphire’s new flagship graphics card, the Toxic HD 7970 GHz Edition 6 GB, has two times as much GDDR5 memory as AMD's reference Radeon HD 7970 GHz Edition board. The company employs the same GPU discussed in AMD Radeon HD 7970 GHz Edition Review: Give Me Back That Crown!, allowing its own Lethal Boost technology (essentially automatic overclocking) to take the chip up to 1200 MHz and the memory to 1600 MHz when thermal headroom allows. The combination of a faster clock rates and extra memory should yield a nice performance boost for the folks who know how to capitalize.
Wait. There are ways to take advantage of all of that memory, aren't there?
Lots of extra RAM is most effective at high resolutions and with lots of anti-aliasing applied. So, that's what we'll be looking most closely at today.

Nothing says big resolutions like an Eyefinity setup composed of six monitors. You might think that we'd need a special Eyefinity Edition of the Radeon HD 7970 to achieve such a thing, but it's indeed possible using a trio of splitters. The only question to answer is whether the card's single Tahiti GPU is fast enough to drive such a massive setup.
Speaking of massive, we decided to go all-out for this little experiment, making it a public event. Our point of comparison was the Radeon HD 7970 from Gigabyte, which we recently reviewed in Gigabyte Radeon HD 7970 Super Overclock: Now With Windforce 5X. For the sake of our head-to-head, we overclocked the Gigabyte board to 1200 MHz, giving us a good baseline for 3 GB versus 6 GB of memory.
Technical Specifications and Features
Sapphire naturally went with AMD's Tahiti GPU for its top-end board, including the built-in TDP limiter that throttles clock rate beyond a set thermal ceiling. We'll be testing to see if that turns out to be a good move. The card's 6 GB of memory running at 1600 MHz represents the most you'll probably ever see from this platform.
Here's how the card's technical specifications size up to AMD's original Radeon HD 7970, the GHz Edition card, and Gigabyte's take on the board:
| Sapphire Toxic HD 7970 GHz Edition | Gigabyte Radeon HD 7970 Super Overclock | Radeon HD 7970 GHz Edition | Radeon HD 7970 | |
|---|---|---|---|---|
| Stream Processors | 2048 | 2048 | 2048 | 2048 |
| Texture Units | 128 | 128 | 128 | 128 |
| Full Color ROPs | 32 | 32 | 32 | 32 |
| GPU Clock | Standard: 1050 MHz Base 1100 MHz Boost Lethal Boost: 1100 MHz Base 1200 MHz Boost | 1080 MHz | 1000 MHz Base 1050 MHz Boost | 925 MHz |
| Texture Fill Rate | 140.8 MHz Gtex/s 153.6 Gtex/s | 138.2 Gtex/s | 134.4 Gtex/s | 118.4 Gtex/s |
| Memory Clock | 1500 MHz 1600 MHz | 1375 MHz | 1500 MHz | 1375 MHz |
| Memory Bus | 384-Bit | 384-Bit | 384-Bit | 384-Bit |
| Memory Bandwidth | 288 GB/s 307.2 GB/s | 264 GB/s | 288 GB/s | 264 GB/s |
| Graphics Memory | 6 GB GDDR5 | 3 GB GDDR5 | 3 GB GDDR5 | 3 GB GDDR5 |
| Die Size | 365 mm² | |||
| Transistors | 4.31 Billion | |||
| Process Technology | 28 nm | |||
| Power Connectors | 2 x 8-pin | 2 x 8-pin | 1 x 8-pin, 1 x 6-pin | 1 x 8-pin, 1 x 6-pin |
| Maximum Power Consumption (TDP) | 320 W | 300 W | 275 W | 250 W |
Sapphire's card features one dual-link DVI, one single-link DVI, one HDMI, and two Mini DisplayPort connectors. This makes the Toxic HD 7970 GHz Edition 6 GB more flexible than even AMD's reference design. The card's bracket employs openings for better ventilation, though its axial fans don't necessarily promote effective exhaust.
| Description | |
|---|---|
| Dimensions | 275 (L) x 115 (H) x 42 (D) mm |
| Included Software | Driver CD Sapphire TriXX |
| In the Box | CrossFire Bridge, DVI-to-VGA Adapter, Mini DP-to-DP Adapter, Active Mini DP-to-DVI Adapter, 6-pin to 2 x 4-pin Power Cable, 1.8 m HDMI 1.4a Cable |
Sapphire's Toxic HD 7970 GHz Edition 6 GB in Pictures
Sapphire’s Vapor-X cooler was developed specifically for this card. Visually, it looks similar to Sapphire's other cards. However, you can see the special vapor chamber under the plastic shroud and two 90 mm fans.
Sapphire deviates from AMD’s reference design with a 12-layer PCB populated with what the company calls its Black Diamond chokes and MOSFETs with DirectFET packaging technology on both sides. The card’s backplate is used to both stabilize and cool the card. We'll go into more depth on this, of course.
The top of Sapphire's Toxic HD 7970 GHz Edition 6 GB has two much-needed eight-pin power connectors.
Sapphire's logo lights up, which looks pretty sharp in the dark.
The cooler employs four heatpipes.
The Sapphire Toxic HD 7970 GHz Edition 6 GB is quite thick, almost making it a three-slot card. You need the right motherboard to run two of these in CrossFire.
- Sapphire Toxic HD 7970 GHz Edition: 6 GB At 1600 MHz
- Board, Cooler, And Power Supply
- Clock Rates And Lethal Boost Mode
- Clock Rates And Power Consumption: Full Load
- Clock Frequencies And Power Consumption: Gaming
- Temperatures And Fan Speed
- Noise Level Comparison Videos
- Building An Eyefinity-Capable System
- Setting Up And Benchmarking Eyefinity 6
- Setting Up And Benchmarking Eyefinity 4
- If You Like Sapphire's Vapor-X, Stick With The 3 GB Card








This.
And this.
Tom's Hardware, if you are going to be reviewing a graphics card with 6 GB of VRAM you have to review at least two of them in Crossfire. VRAM is not cumulative, so using two regular HD 7970 3 GB in Crossfire still means that you only have a 3 GB framebuffer, so for high resolutions with multiple monitors, 6 GB might make the difference.
So, are we going to get an update to this review ? As it is it is useless. Make a review with at least two of those cards with three 30" 1600p monitors. That is the kind of setup someone considering buying one of those cards will have. And that person won't buy just one card. Those cards with 6 GB of VRAM were made to be used at least in pairs. I'm surprised Sapphire didn't tell you guys that in the first place. In any case, you should have figured it out.
Seeing as in both SLI and CFX memory contents are copied to each card, you would practically need that much for ridiculously large screen playing. One card can not handle multiple screens as this was designed for, you need at least two for a x4 screen and three for a x6 screen. The golden rule seems to be two screens per high end card.
This.
And this.
Tom's Hardware, if you are going to be reviewing a graphics card with 6 GB of VRAM you have to review at least two of them in Crossfire. VRAM is not cumulative, so using two regular HD 7970 3 GB in Crossfire still means that you only have a 3 GB framebuffer, so for high resolutions with multiple monitors, 6 GB might make the difference.
So, are we going to get an update to this review ? As it is it is useless. Make a review with at least two of those cards with three 30" 1600p monitors. That is the kind of setup someone considering buying one of those cards will have. And that person won't buy just one card. Those cards with 6 GB of VRAM were made to be used at least in pairs. I'm surprised Sapphire didn't tell you guys that in the first place. In any case, you should have figured it out.
Why not go to the uber-extreme and have crossfire X (4gpus) with six 2500X1600 monitors and crank up the AA to 4x super sampling to prove once and for all in stone.
Thanks for the review. The noise demo alone helps in making a purchase decission.
No sale !
Anyone know why no card has been designed to be turned OFF ( 0 Watts !) when idle, and the system switching to internal graphics for just desktop stuff or simple tasks?
Then applications like Photoshop, Premiere or the ever popular Crisis could 'wake up' the card and have the system switch over.
Or are there cards like that ?
http://www.tomshardware.de/Tahiti-XT2-HD-7970-X-X-Edition,testberichte-241091-6.html
I think that has been applied to laptops, but not on the desktop scene. One of the reasons why I would think its not as useful on a desktop scene is even if your build has stuff off, the PSU is the least efficient when on near 0% load, so no matter what, your still going to burn electricity just by having the computer on. All gpus nowandays have downclocking features when its not being on load(my 7850 downclocks to 300mhz on idle) but I wouldnt think cards will go full out 0.
If these companies - or ourselves - can tackle the noise then such card's traget senario would be realised. Of course, even here, for the rest of us mere mortals we still have one more significant 'hurdle'........cost......so we'll keep waiting.
I realize it is expensive but the review needed another tox for CF and some proper monitors.
Lack luster to say the least. Nothing to say wow about here, I have a feeling 2 or 3 these in cf on water or phase change is something I will have to hunt down myself on the internet
You know since an even number of monitors means youre looking at a lovely seam running right down the middle of your view.
Really? I can think Crossfire and use 6x30" monitors. If you're getting an expensive set up, why not go all the way? This is the Beyron of setups after all!
And yes, it was a very unfair conclusion, since regular people is no the target customer of this kind of card. I thought Toms had more enthusiast blood.
Cheers!