ASUS HD 7790 DirectCU II OC Graphics Card Review

A war is coming. A war over the under $200 graphics card segment. While I can’t tell you who or what is the next shot in this knock down, drag out battle, rest assured this is going to be a fun time at the lower pricing tiers of the graphics card market. AMD gets the first shot across NVIDIA’s bow with today’s announcement of the new AMD Radeon™ HD 7790.

This is a battle for mainstream gaming money. The people that are playing on a single 1080p monitor, are on a budget and don’t mind playing below “Ultra” or maximum detail/MSAA/etc settings. It’s a huge market. While the cards don’t set records or show ZOMG benchmark numbers, this is a huge market segment for both companies, so this is an important moment – for both of them.

Now, let me begin the review with a caveat: As you read this, the HD 7790 has been in my hands almost precisely 36 hours. You will not be treated to my usual, more detailed review. We do the best we can with what is given to us and in the time we have. So right off the bat, I ask your lenience in evaluating my evaluation!

Specifications & Features

The HD 7790 GPU comes with a GCN core featuring 896 stream processors (which makes for 14 compute units) and clocked at 1 GHz. Note that is a reference clock and you may never see an HD 7790 at that speed. The memory signals are delivered by a 128-bit, 1 GB GDDR5 frame buffer. It sips power, drawing only a typical 85W.

Even though it’s not powerful enough to run games on them really, it does allow you to attach up to a maximum of six displays. In a configuration like that, it would make a nice office GPU for a stock trader that needs a lot of monitors but not the gaming power for six monitors.

The best part? This GPU is going to come in as low as $149.00. There will be more expensive and overclocked versions of it, but that’s the base pricing. It’s pretty darn low for a card that’s supposed to do pretty well in its segment.

That’s not all though. The HD 7790 is part of AMD’s Never Settle Reloaded bundle, which means you get a free copy of BioShock® Infinite. That’s a $60 game, free, with a $150 GPU. Color me impressed.

The down side? These aren’t available until April 2nd, so don’t go getting your wallets out yet. It’s good for AMD to get the word out, but bad in that the battle has started. Meaning, delaying until April 2nd may allow something else to come to market with aspirations of competing with the HD 7790. I’m not saying it will, just that the opportunity is there. That would be less of a concern if this was available when the NDA lifted on its reviews.

Bonaire – The AMD Radeon™ HD 7790

AMD’s new chip, codenamed Bonaire, is a new GCN chip, not a revision of existing silicon. It is slightly larger (and more powerful) than the HD 7770 GHz Edition. The chips in this slide are to scale (click on the slide to view it in full size).

Unlike Cape Verde in the previous 7700 GPUs, which only have single Geometry/Tessellation engines, the new Bonaire chip’s diagram looks strikingly similar to the larger 7800/7900 series. As such, it should have more power to handle heavier geometry and tessellation, allowing you to keep game settings turned up higher, even on a budget GPU.

Power Tune has been updated for the new GPU as well. Rather than just four states…

…there are now eight states, so that the GPU operates at the proper voltage for its clock state.

This switching is so fast, it should be completely transparent to the end user.

DirectCompute is a big deal with AMD’s GCN architecture, and here they’re comparing its compute capabilities to NVIDIA’s GTX 650 Ti. You’ll see that competitor throughout as you read about Bonaire, as AMD is aggressively targeting that GPU.

According to AMD’s polling, fully 25% of gamers that use Crossfire go with 7700 series GPUs. To AMD this means a budget-minded consumer may not be able to drop three or four hundred on a GPU all at once, but may still want increased multi-GPU performance down the road. Thus, AMD leaves Crossfire available on even their lower tier cards. In our conference call, they pointed out their target GTX 650 Ti doesn’t have SLI capability.

You’ll never see a reference HD 7790 in the wild. Partners are making all kinds of customized iterations for your consuming pleasure. While the reference clock on this GPU is 1000 MHz, you’ll notice that none of the boards listed below uses the reference clock. The board we’re looking at today is the ASUS HD 7790 DirectCU II OC.

While there aren’t any listed, AMD hinted that there may even be partner cards coming with 2 GB of RAM instead of the reference 1 GB configuration.

It’s relatively obvious, but AMD is positioning this between the HD 7770 GHz Edition and the HD 7850.

Of course, what’s a press deck without company internal testing? Against their targeted competition, AMD shows impressive gains in their own testing.

Here are a few more partner boards for your viewing pleasure before we get into the board we’ll be looking at today.

Now that you’ve seen the company line, let’s look at the GPU we have in-house.

Meet the ASUS HD 7790 DirectCU II

…but first, another company line, this one from ASUS. The specifications as indicated earlier are faster than the stock HD 7790. The DirectCU II OC version clocks in at 1075 MHz on the core, and 1600 MHz on the memory.

ASUS claims their cooler is 20% cooler than the reference design. That’s all well and good and there’s no doubt that’s true, but you’ll never see a reference HD 7790 in the wild, so it’s kind-of moot.

As noted, they will be including GPU Tweak to overclock your card. The version for this card is so new, I didn’t have it when overclocking this card (thus, I clocked without voltage control) but it should be available when these cards hit store shelves.

If you’re familiar with ASUS DirectCU II boards, you’ll be familiar with this packaging and aesthetics. The card comes with a driver CD, setup guide, Crossfire bridge and VGA adapter. It is well packaged to protect it in shipping.

The card itself looks very good for the expected $154.99 MSRP. There are little changes that fit it in-budget. The cooler has two heatpipes instead of three or four on the larger GPUs. The red stripes are red paint rather than shiny red, textured plastic inserts, that kind of thing. Still, it’s a good looking GPU for the money.

Enter the camera…

ASUS is going with the standard video output configuration on their HD 7790, featuring two DVI, one HDMI and one DisplayPort outputs.

While this cooler does put plenty of airflow across the card, the only thing on the card that contacts the cooler is the GPU itself.

As you saw, the PCB doesn’t extend the whole length of the cooler. The power connector on this card is a single 6-pin PCIe connector, plenty for a board in this power range.

So far, so good. I must admit, at the price range, this is a good looking card. Let’s rip the heatsink off, shall we?

Under the Hood

My only complaint here is the thermal “paste”, and I use that term loosely. It’s a budget GPU and you can certainly tell that when you try to remove the TIM. It’s surprisingly hard, both as a property and as a descriptor on difficulty of removal. Most folks won’t be removing the TIM anyway, because there is a little sticker on one of the screws that can tell ASUS if you’ve removed the cooler.

Here is the company line about the DirectCU II cooler on this card.

Now we see the GPU itself. It’s a cute little thing.

Here’s another view of the power connector and on the right we have the power section. There are five power phases on this card, four for the GPU and one for the memory.

Speaking of memory, this one comes with 1 GB of Hynix GDDR5 vMEM clocked at 1600 MHz (6400 MHz quad-pumped).

Now we come to the reason we’re all here – the Bonaire HD 7790 GPU itself.

While it may not be the most robust card on the market, it does look like a clean, well thought out PCB with enough power to suit its purposes.

Test Setup

Our test setup is the same as it has been for a while now, consisting of an Ivy Bridge i7 3770K at 4.0 GHz and memory running at DDR3-1866 / 9-9-9-24. The competition is plenty around and above this card’s price bracket.

**Important note about drivers** The HD 78xx cards graphed in this review have not been re-benched with the 12.x (or later) Catalyst drivers, which showed large performance gains over previous Catalyst versions. We are in the process of reviewing a newer HD 7870 and a HD 7850 is on the way for review as well, so you’ll get those numbers in the future.

Ok, so not many people that get an HD 7790 will be using it on a Maximus V Extreme, but it looks cute on there, doesn’t it?

Cooler Performance & Power Consumption

As mentioned before, the DirectCU II cooler with its two heatpipes and dual 80 mm fans (which ASUS says are dust proof) is far superior to the reference cooler. Additionally, it is absolutely silent. Not once during any of my testing did this card get to the level of my radiator fans (which are running seriously under-volted), even overclocked. If you’re looking for silence in a cooler, you’ve found it in this card. When aided by a cool running GPU, the only card in this graph that gets close to the HD 7790 is another GPU with a DirectCU II cooler. When given an extended load in Heaven, the HD 7790 is by far the coolest running here.

The HD 7790 is not a powerhouse GPU and just sips power. The 184 W mark was in the 3DMark 11 combined test, where the CPU is loaded too. In Heaven and in 3DMark 11 when the GPU is doing the heavy lifting, power draw averaged ~162 W.

Cool running and power sipping, nothing to argue with here.

Overclocking

As mentioned earlier, due to the limited time, we weren’t able to get software to work for voltage control. However, even without it the HD 7790 gave up some impressive numbers. Just turning up the Power Tune limit allowed for a strong overclock of 1250 MHz! Add an extra hundred MHz on the memory (for 1700 MHz / 6800 MHz quad-pumped) and you’ve got a well clocking little card.

Here are 3DMark 11 and Heaven runs testing stability and it’s solid as a rock, passing all our tests without a hiccup.

Add another notch in the HD 7790’s belt for solid clocking.

Performance Results

All of our benchmarks are run per our GPU testing procedure guidelines, which you can check out right here. Long story short: benchmarks are run at their default settings and games are run with everything maxxed. Because of the previously mentioned driver notes re: HD 78xx GPUs, I’ll keep my comments between the GTX competition and the HD 7790.

Synthetic Tests

AMD has ruled 3DMark03 this generation in every price bracket and this one is no different. It’s not necessarily relevant to anything today, but it’s fun for benchmarkers at least.

Getting to relevant testing, the HD 7790 has a stout showing against the 650 Ti. The GTX 660 is a fair bit ahead though.

With its increased tessellation processing power, the HD 7790 does a good job of separating itself from the GTX 650 Ti and begins to approach the GTX 660.

Heaven is also very Tessellation heavy. While the separation at stock with the GTX 650 Ti isn’t huge, the overclocked HD 7790 jumps ahead by a lot.

So far it looks like it does its AMD-stated job and beats the GTX 650 Ti. It even gets almost close to the GTX 660, but not close enough to make it a true competitor. The GTX 660 Ti is just out of the HD 7790’s league.

Game Tests

Now to some more real world testing. AvP is usually AMD-friendly, but the GTX 650 Ti gives the HD 7970 a run for its money. The GTX does lose, but not by much.

Batman paints a prettier picture for the HD 7790, with solid gains over the GTX 650 Ti.

Again, not a large difference, but a definite win for the HD 7790 over the GTX 650 Ti. At this point it’s safe to say none of the other cards are in danger of getting beaten by the HD 7790.

Same story, different bench. Consistently beating your targeted card is good though.

Dirt 3 is the only game in which the GTX 650 Ti beat the HD 7790, even overclocked.

Metro is back to the proper pecking order.

Except for Dirt 3’s bucking of the trend, AMD put the GTX 650 Ti in their sights and took it out.

Please accept my apologies, but there will be no “pushing the limits” section because I have neither the voltage control nor the time.

Final Thoughts & Conclusion

Let’s start with price. The base HD 7790 price is $149.99. This particular iteration, with a stout cooler and typically good looking ASUS style is expected to go for $154.99. $5 is a pretty easy hit to take for that trade off. So you have a $154.99 card that does exactly what AMD said it would – beat the GTX 650 Ti.

The HD 7790 was designed for those folks that need a budget GPU and want to exercise that GPU on a 1080p monitor. This audience doesn’t mind turning MSAA very low or off and setting detail to “High” (“Medium” in some games, like Metro 2033 and its ilk) in order to get a good gaming experience and come in at a reasonable price point. I think this GPU is perfect for this audience.

It’s not the only audience that would benefit from something like the HD 7790. This card is perfect for the HTPC crowd. Cool running? Check. Run 1080p at decent settings? Check. Power sipping? Check. It even overclocks nicely. Put that in a package with a small PCB like this, and you’ve got a very respectable contender for your HTPC consideration.

For a hundred fifty bucks, I think the HD 7790 is a good card for the money. However, keeping with the war analogy, NVIDIA has already started moving its armies. There is an MSI GTX 650 Ti that has come down to $140 ($114 after mail in rebate). There are others that maintain the $150 price point, but have $20 mail in rebates. Does this portend another battle in the ongoing war for your gaming dollar? I guess you’ll have to keep checking our site.

Until something changes though, AMD has done exactly what it said it would and has beat the GTX 650 Ti. The real icing on the cake is AMD’s Never Settle Reloaded bundle, which gives you Bioshock Infinite (from most places a $60 game) free when you buy this card. That’s going to be a tough value-add to beat. $150 card for $210 worth of card and game sounds mighty good to the budget gamers in this target market.

– Jeremy Vaughan (hokiealumnus)