MSI’s DKA790GX Platinum motherboard

The Phenom II has arrived, and in some respects, it’s better than expected. The X4 940 won’t give a Core i7-965 Extreme a run for its money, of course, but we enthusiasts tend to shy away from the high end of the market anyway. We’d rather take a less expensive CPU, pair it with an equally affordable motherboard, and overclock and tweak the snot out of both to deliver the best performance per dollar with the smug satisfaction of knowing we pulled one over on The Man. Or something.

At less than $300, even the flagship Phenom II X4 940 Black Edition qualifies as inexpensive. And unlike with Intel’s latest batch of Nehalem-derived Core i7 processors, motherboards compatible with Phenom II chips are both plentiful and affordable. Boards like MSI’s new DKA790GX Platinum, for example, are easily found for under $150.

Armed with AMD’s jack-of-all-trades 790GX chipset, the DKA790GX offers a unique combination of potent integrated graphics with dual PCI Express x16 slots for CrossFire. Pile on DVI and HDMI output options, six Serial ATA ports, the usual mix of integrated peripherals, and a BIOS primed for overclocking, and we have what looks to be a great companion for AMD’s latest 45nm processors. Read on to see how the DKA790GX fares with Phenom II onboard.

The board
We’ve already covered AMD’s 790GX chipset in great depth, so we won’t dwell on it here. If you’re unfamiliar with this core logic Swiss army knife, I suggest checking out our initial review of the chipset.

Perhaps lying in waiting for Phenom’s second coming, motherboard makers haven’t pimped the 790GX quite as aggressively as they have other chipsets. Asus and Gigabyte are known for releasing a multitude of motherboard flavors based on a single chipset, yet both offer only one option based on the 790GX. MSI at least serves up two models, although they’re essentially different versions of the same board. Today we’ll be looking at the Platinum version of the DK790GX, which adds a black color scheme and Firewire support at about a $23 premium over its vanilla cousin.

The Platinum’s layout is quite roomy, but then that’s to be expected given that the board isn’t loaded down with superfluous auxiliary peripherals and exotic accessories. At first glance, you’ll notice that the layout itself is a little unconventional, too. The south bridge chip sits a little higher on the board than usual, and so does the north bridge chip, which is more next to the CPU socket than below it.

MSI optimizes the DKA790GX’s power plug placement for traditional enclosures that put the PSU above the motherboard. The auxiliary 12V connector is located along the top edge of the board where cabling won’t interfere with the CPU socket in a standard case. However, if you’re using an upside-down enclosure that puts the PSU below the motherboard, you’ll likely need an extension cable for the 12V line. Despite only offering a four-pin auxiliary 12V connector, the Platinum still supports processors with TDP ratings up to 140W.

If you’re planning on plunking in a power-hungry processor, you’ll probably want to pair it with a larger aftermarket cooler. The Platinum’s socket area should be able to accommodate most oversized heatsinks. Although the north bridge cooler and DIMM slots are a little close to the socket for my liking, the board has just enough clearance for Scythe’s gargantuan Ninja tower.

Despite its hopped-up integrated graphics core, the 790GX runs pretty cool. The Platinum gets by with only modest heatsinks on its north and south bridge components, although the two are linked by a couple of long heatpipes. MSI also equips the board’s voltage circuitry with a passive heatsink that lies separate from the chipset heatpipe network.

After reviewing a wave of high-end X58 motherboards loaded down with all sorts of auxiliary storage options, the DKA790GX’s Serial ATA cluster looks almost barren. And yet it still offers five SATA ports hanging off AMD’s latest SB750 south bridge, with a sixth port routed to an eSATA plug in the rear port cluster. Four of the five internal SATA ports are mounted along the edge of the board and the fifth is strategically placed to ensure that none are obscured by double-wide CrossFire configs.

To the left, notice that MSI has equipped the Platinum with power, reset, and clear CMOS buttons. The convenience of onboard power and reset buttons is great when working on an open test bench, but I have to admit that the utility of these extras will likely be lost on most end users. MSI would do well to move the clear CMOS button into the rear port cluster where it can easily be accessed without the user having to remove a case panel.

The DKA790GX’s slot stack sports pairs of PCI Express x16, x1, and standard PCI slots. Of course, the 790GX chipset doesn’t have enough PCIe lanes for a true dual-x16 implementation, so the x16 slots get eight lanes of bandwidth each. Since they’re second-generation PCI Express, though, the x8 links deliver equivalent bandwidth to x16 gen-one links.

MSI has arranged the slots so that a double-wide CrossFire config still leaves you with available PCIe x1 and standard PCI slots, which is a nice touch. From here we also get a good look at the board’s capacitors, which are of the solid-state variety. I haven’t burst a cap in years, but I lost a few motherboards to faulty electrolytic capacitors back in the day, so I can appreciate the industry’s recent fixation on higher-quality electrical components in enthusiast-oriented motherboards.

You get a little bit of everything in the Platinum’s port cluster—well, a little of everything except a PS/2 mouse connector. That omission will likely flummox those with older KVM switches, but those with old-school clickety-clack keyboards should appreciate the inclusion of a PS/2 keyboard port. At least the DKA790GX is loaded on the video front, with VGA, DVI, and HDMI outputs all stemming from the chipset’s integrated Radeon HD 3300 graphics core. Since the Radeon HD 3300’s video decode block is capable of full Blu-ray decode acceleration, the HDMI output is particularly appropriate. It’s also worth noting that MSI pairs the 790GX’s integrated Radeon with 128MB of dedicated DDR3-1333 memory.

Six USB, one Firewire, and one eSATA port fill out the Platinum’s cluster of peripheral connectivity options. Realtek provides the silicon behind the board’s Ethernet and audio ports, although MSI settles on the relatively pedestrian ALC888 codec, as opposed to the Soundstorm-esque ALC889A. The ALC889A’s ability to encode Dolby Digital Live bitstreams on the fly would have nicely complemented the Platinum’s digital audio output.

BIOS options
Windows overclocking and tweaking software has improved by leaps and bounds over the years, most recently with AMD’s own OverDrive utility, which allows for per-core multiplier control among other perks. Maybe it’s because I’m getting old and think things were better the way they were, but I still prefer tweaking and overclocking via a motherboard’s BIOS. Fortunately, the DKA790GX’s BIOS is stacked with enough options to keep most tweakers and overclockers happy.

Phenom overclocking is best done with an unlocked upper multiplier, and the Platinum provides more than enough CPU multiplier options in 0.5X increments. If your processor’s upper multiplier is locked, the DKA790GX also supports base clock overclocking up to an impressive 600MHz.

Those who overclock by increasing the processor’s base clock will want to keep other system components in check, and the Platinum’s BIOS has no shortage of bus dividers and multipliers to make that happen. Users can easily adjust the HT multiplier to control the speed of the chipset’s processor link, for example. The BIOS also serves up a handful of dividers that can adjust the memory bus speed between 400 and 1066MHz. AMD only officially supports 1066MHz memory speeds with one DIMM per channel, though.

Our DKA790GX Platinum’s first BIOS revision wasn’t particularly happy running even two memory modules at 1066MHz, but upgrading to the latest 1.4 release quickly remedied the stability issues we experienced. And it’s a good thing, too, because the Platinum’s BIOS bristles with memory timing controls for those who want to wring as much performance as possible from their memory.

MSI is one of only a few motherboard makers offering a reasonable amount of BIOS-level automatic fan speed control. On the DKA790GX, one can set a target CPU temperature between 40 and 60°C in five-degree increments. It’s also possible to adjust the minimum CPU fan speed between 0 and 87.5% in 12.5% increments. The BIOS’s system fan speed control is decidedly more limited, though; it’s not temperature controlled, and you only have the option of setting the system fan speed at 50, 75, or 100%.

Specifics on specifications
We’ve consolidated all the key specifications of the DKA790GX Platinum below.

Since we’ve already covered the Platinum’s highlights, I won’t spend too much time on the chart above. However, it is worth noting that the DKA790GX uses Realtek’s older RTL8111C Gigabit Ethernet chip, which is one step behind the new and improved RTL8111D revision. It’s also interesting to see Firewire supplied by a JMicron chip rather than more common alternatives from Texas Instruments and Via. JMicron’s IDE and SATA storage controllers have become quite popular over the last couple of years, but they’re not exactly known for their performance.

Our testing methods
Today we’ll be comparing the DKA790GX Platinum’s performance with that of another board based on AMD’s 790GX chipset, Gigabyte’s GA-MA790GP-DS4H. You can get the full scoop on the Gigabyte board in our 790GX launch coverage.

All tests were run three times, and their results were averaged.

All of our test systems were powered by OCZ GameXStream 700W power supply units. Thanks to OCZ for providing these units for our use in testing.

Thanks to Corsair for providing the Dominator DIMMs we used for testing.

Finally, we’d like to thank Western Digital for sending Raptor WD1500ADFD hard drives for our test rigs.

We used the following versions of our test applications:

• SiSoft Sandra Standard 2009 15.42

• WorldBench 6.0 Beta 2
• HD Tach 3.03
• Call of Duty 4 1.4
• RightMark Audio Analyzer 6.06
• NTttcp
• CASE Lab Euler3d CFD benchmark multithreaded edition
• Far Cry 2 1.01
• Enemy Territory: Quake Wars 1.4
• Half-Life 2: Episode Two
• CPU-Z 1.41

The test systems’ Windows desktop was set at 1280×1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests.

All the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.

Memory performance
The Phenom’s integrated memory controller largely takes the motherboard out of the equation when it comes to memory subsystem performance. However, motherboard makers do have some freedom when it comes to tuning the CPU’s memory controller.

There’s virtually no difference in the memory bandwidth available to each board. The Platinum does lag behind the Gigabyte board by just over two nanoseconds in our memory latency test, though.

Motherboards don’t always play nice when all of their DIMM slots are populated, so we popped a couple of extra memory modules into each board to see how they fared. Unfortunately, neither was able to overcome the Phenom II’s lack of official support for more than one DIMM per channel at 1066MHz, so we had to back off the memory speed to 800MHz on each board. For what it’s worth, the Gigabyte board refused to post with four DIMMs at 1066MHz. The MSI posted, but then spat up a blue screen on the way to Windows.

Again, we see little difference in available memory bandwidth between the two boards. The DKA790GX continues to trail the Gigabyte in our memory latency test, though, this time by a little less than two nanoseconds.

STARS Euler3d computational fluid dynamics
Few folks run fluid dynamics simulations on their desktops, but we’ve found this multi-threaded test to be particularly demanding of memory subsystems, making it a good link between our memory and application performance tests.

Despite a slightly more sluggish memory access latency, the Platinum edges out the DS4H in our fluid dynamics benchmark.

WorldBench
WorldBench uses scripting to step through a series of tasks in common Windows applications. It then produces an overall score. WorldBench also spits out individual results for its component application tests, allowing us to compare performance in each. We’ll look at the overall score, and then we’ll show individual application results alongside the results from some of our own application tests.

The MSI has two points on the Gigabyte in WorldBench. Scores are close through most of the suite’s individual application tests, but the Platinum has enough of an advantage in the Firefox, multitasking, and WinZip tests to build a small overall lead.

Gaming

Gaming performance is essentially identical when these boards are paired with discrete graphics cards.

Power consumption
We measured system power consumption, sans monitor and speakers, at the wall outlet using a Watts Up Pro power meter. Power consumption was measured at idle and under a load consisting of a multi-threaded Cinebench 10 render running in parallel with the “rthdribl” high dynamic range lighting demo. Results that fall under “No power management” were obtained with Windows Vista running in high-performance mode, while those with power management enabled were taken with Vista in its balanced performance mode.

The DKA790GX Platinum proves more frugal than the DS4H at both idle and under load. MSI’s power efficiency advantage ranges from four to seven watts, which isn’t much, all things considered.

Overclocking
For quite some time, it’s been difficult to recommend AMD processors that don’t have unlocked upper multipliers, and that hasn’t changed with Phenom II. Curious to see just how far our X4 940 would overclock on the DKA790GX Platinum, we dipped into the BIOS and started fiddling with the CPU multiplier, testing stability along the way with a Prime95 load on each of the CPU’s four cores.

Since Phenom II processors have Advanced Clock Calibration (ACC) goodness built-in, there’s no need to enable the feature in the Platinum’s BIOS. You’ll want to turn it on if you’re using an older 65nm Phenom, though.

Our Phenom II didn’t get far with its stock voltage, but cranking the CPU up to 1.4V yielded a stable 3.4GHz with a 17X CPU multiplier. Not content to stop there, we dialed the multiplier up to 17.5X, yielding a 3.5GHz processor clock. This speed wasn’t stable under load without an additional voltage bump, this time up to 1.4375V. We couldn’t even get the board to post at 3.6GHz, though—not even with extra voltage and a virgin sacrifice.

Of course, as is always the case with overclocking, your mileage—and the actual purity of your sacrifice—may vary.

Motherboard peripheral performance
Some of the biggest performance differences you’ll find between motherboards come on the peripheral front, where it’s easy to spot where mobo makers have skimped on auxiliary peripheral chips.

The DS4H uses a newer version of Realtek’s RTL8111 Gigabit Ethernet controller than the MSI board, and there’s a sizable difference in CPU utilization between the two. That said, the Platinum’s GigE throughput is all but identical to that of the Gigabyte board.

The DKA790GX’s JMicron Firewire chip has decent read performance and CPU utilization, but its sustained write speeds pull up 6MB/s short of the DS4H.

Given that the MSI and Gigabyte boards use the same AMD SB750 USB controller, it’s disappointing to see the Platinum turning in slower sustained read and write speeds.

Again, the DKA790GX’s peripheral performance pulls up a little lame. Serial ATA read speeds, write speeds, and access times look good for the Platinum, but the board’s CPU utilization is more than three times that of the DS4H. HD Tach’s margin for error in the CPU utilization test is +/- 2%, but that still leaves the MSI board at a disadvantage here.

We ran RightMark Audio Analyzer with a 24-bit/192kHz loopback test, which yielded the same overall score for each board. However, it’s worth noting that the Platinum only scores higher than the DS4H in one of RMAA’s individual tests, while the Gigabyte board comes out ahead in four.

Conclusions
I have to admit that I’m still not really sold on the 790GX chipset. It’s a loaded jack of all trades, no doubt, but one that marries seemingly contradictory graphics options. Pairing reasonably quick integrated graphics with a pair of physical PCI Express x16 slots that provide far superior gaming performance potential may be great for those who favor piecemeal upgrades, but it seems like a waste to me. Still, the 790GX is AMD’s mid-range chipset for Phenom processors, and that’s what motherboard makers have to work with.

MSI has done a pretty good job exploiting the 790GX with its DKA790GX Platinum. The integrated Radeon HD 3300 is paired with HDMI and DVI video outputs, which are handy, and the x16 slots are nicely spaced for double-wide CrossFire combos. MSI’s decision to route one of the south bridge chip’s Serial ATA ports to an eSATA connector in the port cluster was a smart one, too. This arrangement allows users to mirror the contents of their primary hard drive on a fast external drive that’s easily portable.

Those looking to fiddle with memory timings, clock speeds, and voltages will no doubt be pleased with the options provided by the Platinum’s BIOS. The voltage ceilings might be a little low for the liquid nitrogen crowd, but casual overclockers and those who don’t employ exotic cooling methods should have plenty of room to stretch their processors’ legs. MSI serves up better BIOS-level automatic fan speed tweaking controls than most of its competitors, too.

Unfortunately, the DKA790GX also has relatively poor peripheral performance when compared to its direct competition. While the Platinum is every bit as fast as the Gigabyte board we tested in common desktop applications and games, the MSI board has a slower Firewire chip, lower USB throughput, and a Gigabit Ethernet controller that consumes more CPU cycles. The DKA790GX’s audio codec lacks on-the-fly Dolby Digital Live encoding capabilities, as well, preventing users from enjoying multi-channel digital output in games and other applications that don’t have pre-encoded audio tracks.

If the DK790GX were much cheaper than the competition, I’d be more inclined to forgive its shortcomings. But at around $147 online, it actually sits at the high end of the 790GX motherboard spectrum—and it’s more expensive than the Gigabyte board, too. So, while the DKA790GX Platinum is surely a solid board, there are better options for prospective Phenom II buyers.