Archive Home arrow Reviews: arrow Video Cards arrow PowerColor AX6990 4GBD5-M4D Video Card

PowerColor AX6990 4GBD5-M4D Video Card E-mail
Reviews - Featured Reviews: Video Cards
Written by Bruce Normann   
Sunday, 20 March 2011
Table of Contents: Page Index
PowerColor AX6990 4GBD5-M4D Video Card
Closer Look: PowerColor Radeon HD 6990
PowerColor Radeon HD 6990 Detailed Features
Features and Specifications
Video Card Testing Methodology
DX10: 3DMark Vantage
DX10: Just Cause 2
DX9 SSAO: Mafia II
DX11: Aliens vs. Predator
DX11: Battlefield: Bad Company 2
DX11: DiRT-2 Demo
DX11: H.A.W.X. 2
DX11: Lost Planet 2
DX11: METRO 2033
DX11: Unigine Heaven 2.1
PowerColor HD 6990 Temperatures
AMD Radeon HD 6990 Final Thoughts
PowerColor Radeon HD 6990 Conclusion

PowerColor Radeon HD 6990 Detailed Features

Each GPU gets its own PWM-based VRM power section, with an independent 4-phase supply delivered directly to each Cayman-class GPU. The power MOSFETs and their driver transistors are integrated into a DrMOS design from Volterra, although I don't think they use that name for their products. They're the eight shiny IC packages below the large white inductor modules. The power supply chokes for the GPU circuit are from Cooper Bussmann, one of the oldest trade names in the power component business. AMD is using these modular chokes on almost all their high power reference designs lately; I think they first showed up on the HD 5870.


There are two Volterra VT1556 PWM controllers mounted on the back side of the PCB, providing all the high level voltage control functions. This part is a holdover from the Radeon HD 6950 and HD 6970 reference cards, where only one controller was required for the single GPU. The controller offers I2C communication and control, so someone will undoubtedly build an interface into their monitoring and control software. The fact that every HD 6900 series card uses the same controller pretty much guarantees it.

The memory and the PCI Express bridge chip get their power from a smaller set of PWM power supply sections located in the center again, only along the bottom edge. The individual filter chokes can be seen at the top of the image above, and it looks like the memory is getting 2-phase power with the PCI Bridge getting a single-phase. Speaking of the bridge chip, it is a re-branded PLX item, and is the same part that was used on the Radeon HD 5970 card. I'm guessing that AMD had a large stock of them from previous orders, because they still have the ATI logo on them.


This little switch is what unlocks the power of this card, literally. The board ships with the switch in position 2, where it limits the GPU core clock speed to 830 MHz, and the core voltage to 1.120 volts. Capping those two parameters keeps the overall power consumption at or below 375 watts, which is technically all the various connectors are supposed to be able to supply. It also keeps the heat down, to where the fan is not overly loud in order to keep the GPU temps below 80C in continuous gaming use. If you want to take it further, you first have to remove the yellow warning sticker which refers you to the product manual for all the dire consequences that can occur if you proceed. Once you agree to void the product warranty and flip the switch to position 1, the GPU clock is automatically bumped up to 880 MHz and the default GPU core voltage goes up from 1.120V to 1.175V.

WARNING: AMD's product warranty does not cover damages caused by overclocking, even when overclocking is enabled via AMD software and/or the Dual-BIOS Function on the AMD Radeon HD 6990. This restriction is carried through by PowerColor and almost every other AMD AIB partner.


All of the reference Radeon HD 6990 cards feature 4GB of GDDR5 frame buffer memory, and surprisingly, the memory modules used are the lower speed devices that were previously seen on the HD 6950. The Hynix H5GQ2H24MFR-T2C components are rated at 1250 MHz and can reach 5.0 Gbps bandwidth with a 1.5V supply, which is what AMD is using in this application. The stock Radeon HD 6970 cards have a 1375 MHz memory clock, and require the "-ROC" version of this chip to run at that speed.


The PC board had good solder quality and precision component placement, as you can also above. I've not seen this much bare traces before on any card; most times the solder flows over the entire pad, leaving nothing exposed. It's not a case of not enough solder being used for the joints, each connection I see has an ample amount to serve its dual function of holding the part in place and an electrical connection. This is the area on the back side of the board, directly below the GPU, and it's one of the most crowded sections of any graphics card. On my LCD screen, this image is magnified 20X, compared to what the naked eye sees. The smallest SMD capacitors located in this view are placed on 1mm centers. The board surface was also quite clean, which is always a good thing.


The I/O plate has a new configuration that is optimized for both airflow and multi-monitor display setups, AKA Eyefinity. By putting all the display connectors in one row, the size of the cooling vent could be maximized, which is critical for this high-powered beast. The use of all mini Display Port connections allowed a total of five connections, although only four can be active at any one time. PowerColor includes three miniDP adapters in the package: 1-Passive miniDP to Single Link DVI, 1- Active miniDP to Single Link DVI, and 1-Passive miniDP to HDMI. That's an impressive collection of adapters, which should help all of us who are just getting used to Display Port and still require support for legacy monitors.

Before we move into the testing phase of the review, let's take a detailed look at the features and specifications for the new AMD Radeon HD 6990 video card. AMD and PowerColor have supplied us with a ton of information, so let's go....



# RE: PowerColor AX6990 4GBD5-M4D Video CardRobert17 2011-03-20 15:16
Well done Bruce. After all the effort, sacrifice, and no telling how many years of enthusiasm/experience you bring to the fray, I feel compelled to offer a sacrifice of my own. Since the card is out of warranty, I volunteer to take it off your hands for long term testing, say a couple of years, and deal with any and all warranty issues in your stead. I know, I know, my altruism knows no bounds.

(wink, wink, nudge, nudge)

Good job.
Report Comment
# Counter OfferBruceBruce 2011-03-20 16:19
Thanks for the props, Robert. As for your boundless altruism, I'll go you one better. You put gas in my wife's car for the time that you have the card, and it's a deal. [%^)
Report Comment
# RE: Counter OfferRobert17 2011-03-20 16:22
Does she actually drive it?
Report Comment
# Just got mineCom-Tek Chris 2011-03-22 06:43
I know this was written for the PowerColor card but I just received my HIS yesterday and installed it last night. I guess my bottle neck is my resolution and my monitor. I have a 28" 60Hz, 1920x1200 Hanns-G monitor with 3ms response. I just don't see the gain from this series and going back to my 2x 465 GTX Nvidias or my 2x 580 GTX's in SLI. For the ATI fans I also have 2x 5850's in X-Fire and they also run like beasts. Its kinda like having a Race Car that does 205+ MPH but because you live in a heavy school zone there are always police which limits your choice to either follow the law or get arrested (Kind of a bad analogy but I'm sure you get my drift).

So now I have spent $720 on this card, damn I need a new hobby, I've now spent over $2,500 on video cards in the last 6 months.
Report Comment
# RE: Just got mineOlin Coles 2011-03-22 07:17
I'm curious what kind of games you're playing, because that could be an indication of your bottleneck. Anything will play Battlefield or Starcraft at high frame rates, but the same cannot be said for titles such as Metro 2033.
Report Comment
# RE RE: Just got mineCom-Tek Chris 2011-03-22 07:33
I'm playing Battlefield Bad Company 2 and a few other FPS games. I figured that was my problem. And BFBC2 is more CPU intensive, I playing Battlefield on my AM3 1090T 6 Core which is more than enough for that game. I need to start HA (Hardware Anonymous) for geeks, but I'm afraid it would be a blood bath of which brand name was better, lol.
Report Comment
# A thoughtCom-Tek Chris 2011-03-22 06:59
How come we are pitting this against the Nvidia 400 series and not a set of 560ti's in SLI or a a single 580 GTX? I notice that the scores are up against a set of 460 GTX's in SLI and a couple of 6xxx series in cross-fire mode but none of the big cards from Nvidia in SLI. Was this because of a price to power thresh hold? Or because of availability in cards? I know my 2 580 GTX's his the $1,100 mark when I purchased both so maybe it is unfair to compare it to a single card that is $400 less, but still it would be nice to have the scores posted for comparison for both sides of the fan base. Hands down though, I love this 6990, its fast, sweet, and feels like there is a lot of technology in it. Even Nvidia Fan Boys would be impressed with the sheer speed of this card.
Report Comment
# RE: A thoughtOlin Coles 2011-03-22 07:18
If we had two of everything, we'd put them in SLI or CrossFire. Since one card arrives as another is ready to launch, we're restricted by deadlines and must move to the next project.
Report Comment
# RE RE: A thoughtCom-Tek Chris 2011-03-22 07:34
Do you have to send back the cards your given? If not what do you do with them? Or do I dare ask, lol.
Report Comment
# RE: RE RE: A thoughtOlin Coles 2011-03-22 07:37
Only a few products get returned, but it's a matter of finding time to review more than one product of the same series before the next arrives. These reviews take more time than you could imagine (I invite you to try sometime), and after one article in published a manufacturer usually has something new in our hands.
All of my video cards sit in a giant cardboard box, and get sold about 16 months after they've launched and gone EOL.
Report Comment
# RE: RE RE: RE: A thoughtCom-Tek Chris 2011-03-22 08:43
I have done Bench Marking in the past with all new hardware, always trying to squeeze that extra 100 points out, lol, I don't do much anymore just because of the time it takes. I am a business owner and there are days where I start at 6am and get home at 10pm only to find that I have a 1/2 dozen build outs that are to be done by the next am, so I pull a 24hr shift that turns into a good 36hr shift, lol, did I mention I have a wife and 5 kids? the drama continues in the life of "Im a computer engineer/network security consultant/Father/Guy who likes to game/Guy who races cars in the SCCA in the season which is here now/Guy who builds computers and provides support for local residents and business's and also donates computers to new local schools that burnt down 2 years, lol, yes I love life and all it offers..........did I mention I love Chinese food and hot pockets?
Report Comment
# RE: RE: RE RE: RE: A thoughtOlin Coles 2011-03-22 08:48
Replace kids with friends, keep computer engineer/network security consultant/SCCA racer, and add target shooting enthusiast. Also replace Chinese food with Thai, and hot pockets for Wheat Thins, and we're on the same page.
Report Comment
# Thanks BruceCom-Tek Chris 2011-03-22 07:15
Thanks Bruce for the in-depth article, it was very informative and I'm sure will encourage decisions on owning this card. Keep up the good work.
Report Comment
# You're WelcomeBruceBruce 2011-03-22 20:34
Olin's spot on about product availability v. time to do the review. As Einstein said, "The reason time exists is so that everything doesn't all happen at once." My corollary to that is, "Space exists so that everything doesn't all happen at the same place."

So, check out Olin's HD 6990 reviews for comparisons to the GTX 570 and 580 cards. I was surprised that the 580 SLI didn't wipe the mat with the competitors. It was faster, but not in another league, you know....

I'm very curious to see how well NVIDIA manages the balance between electrical power, heat and processing power with their rumored dual-GPU card. At this stage of the game (40nm GPUs), there's only so much juice that you can pump through a single card and the winner is the one that's more efficient per watt. We'll have to wait another week or so, to see.

FWIW, I prefer Triscuits....LOL
Report Comment
# RE: You're WelcomeOlin Coles 2011-03-22 20:37
Ah, Triscuits and wine cheese. One of my nostalgic favorites!

PS: Check back here at 6AM PST on 03/24 for "The Next Big Thing".
Report Comment
# RE: RE: RE RE RE: RE: A thoughtCom-Tek Chris 2011-03-22 09:07
My wife pushes the wheat thins/Crackling Oat Bran Cereal.....a lot! And I just tried Thai recently, the curry wasn't to bad. My goal is to lose 30 pounds this year. I just got over the Flu and I have kept 12 pounds of that off, lol, its going to be a good year. Now if I can just get my hands a new AM3+ 8 Core, another 6990 for X-Crossfire Mode, now that would finish the year off with a POW!
Report Comment
# PC Case SizeVaughn Janes 2011-03-22 16:49
What PC Case do you have in that picture, I hope its not really expensive. If it is do you think you could link a cheaper Pc case?
Report Comment
# CM Storm SniperBruceBruce 2011-03-22 17:30
It's a CM Storm Sniper, which I reviewed here:

It's not cheap, unfortunately, unless you find a deal. The good news is that there have been a ton of inexpensive gaming chassis reviewd on this this site recently, and I'd bet at least half of them would be able to handle this card, at 305 mm long.
Report Comment
# Forgot to make it a replyVaughn Janes 2011-03-22 17:39
Ok Coolio, its way cheaper than the one I found ( Thanks.
Report Comment

Comments have been disabled by the administrator.

Search Benchmark Reviews

Like Benchmark Reviews on FacebookFollow Benchmark Reviews on Twitter