Verdict: The Gravistar is flamboyant in all the right ways

Contrary to what we expected, the Gravistar isn't this year's most expensive Dream PC: that dubious honour goes to the SavRow. We suspected that the Gravistar would be the most expensive PC because Armari has a reputation for putting together top-notch business systems, such as £70,000 16-way Opteron rackmount servers with 128GB of RAM.

Like four of the other Dream PCs, the Gravistar is based around AMD's flagship processor, the Athlon 64 X2 4800+. Of course, it wouldn't be wise to submit a non-overclocked Dream PC and in the Gravistar, the CPU is pre-overclocked from 2.4GHz to 2.64GHz by raising the FSB from 200MHz to 220MHz. The memory comprises two 512MB Corsair XMS4400 DIMMs running at 440MHz.

The Asus A8N-SLI Deluxe seems to be the motherboard of choice right now, but Armari has gone one step further with the Gravistar by including the updated A8N-SLI Premium.

The Premium boasts superior overclockability and more BIOS options than the Deluxe. The graphics cards are a pair of XFX GeForce 6800 Ultras, pre-overclocked from 425MHz/1.1GHz to 440MHz/1.15GHz.

The chassis is a Koolance PC3-726BK, which is loosely based on a Lian Li design, with an Exos-2 water-cooling system fully integrated into the roof. This innovatively designed case separates the guts into two separate compartments, one for the motherboard and 5.25in drive bays, and the second for the 3.5in drive bays and PSU. The cooling system comprises two entirely separate loops, one for the CPU, and the other for the graphics cards and Northbridge. The CPU is cooled by a standard water-cooling system, which consists of the Exos-2 and a single 120mm-fan radiator at the back of the case.

This loop is also responsible for cooling the two 226W TECs mounted on either side of the Swiftech MCW-Chill 452 water chiller. These TECs in turn pre-cool the coolant passing through the central chamber of the MCW-Chill 452, which is then pumped out to the waterblocks on the graphics cards and Northbridge. A separate controller PCB monitors the temperature of the TECs and changes their input current accordingly. When typically run at 300W, the MCW-Chill 452 pre-chills the coolant to around 18.5ûC. This arrangement ensures that the graphics cards and Northbridge receive a steady flow of pre-chilled coolant that's cooler than room temperature. Armari has also modded the notoriously hot-running Meanwell TEC PSU with an additional 80mm fan, fitted a small 40mm fan to the motherboard VRMs, added a second 80mm fan to blow cool air over the graphics cards' VRMs and mounted a 120mm fan at the front to cool the hard drives and PSU. It's easy to see what the Gravistar is doing too, as two displays in the front panel monitor the temperature of the coolant exiting the water chiller and the CPU waterblock. The Exos-2 also has its own temperature monitor and can adjust the speed of its two 120mm fans.

Three 300GB Seagate Barracuda 7200.8 hard drives are installed in a separate compartment at the bottom of the case and are attached to an XFX Revo64 S-ATA RAID controller. The drives are configured as a RAID 3 array that combines the attributes of RAID 0 with RAID 5. So what you end up with is a fast 600GB partition backed up by the third drive, which stores parity bit data. Tucked away behind the hard drives is a super-quiet Enermax PSU with twin 18A 12V rails. The Sony DRU-800A is a dual-layer DVD writer. The monitor is our current Elite-listed choice, a ViewSonic VP201b. This 20in TFT has a native resolution of 1,600 x 1,200 and is ideally suited to displaying fast-moving games and movies. As with all the Dream PCs, sound is handled by a Sound Blaster Audigy 2 ZS sound card, in this case partnered with a 5.1 set of earthquake-generating Logitech Z-5500 Digital speakers. A Logitech Cordless keyboard and Logitech MX1000 mouse round off the bundle.

PERFORMANCE

As you'd expect, a PC with an overclocked Athlon 64 X2 4800+, 1GB of RAM and two overclocked GeForce 6800 Ultras shouldn't be a slouch in our benchmarks, and the Gravistar is no exception. In fact, it racked up the fastest score of any Dream PC in the video encoding test, leaving systems such as the Real Machines and Holly eating dust.

Running multiple tasks at the same time is no problem for the Gravistar, thanks to its dual-core CPU; it averaged 67.4fps in Far Cry at 1,600 x 1,200 with 4x AA and 8x AF while ripping an audio CD. With its pre-chilled and multiple-loop cooling system, the Armari flew through our overnight folding stress test without even breaking sweat.

CONCLUSION

With its two separate cooling loops and graphics card pre-chiller, the Gravistar is a damn impressive example of industrial engineering. Having two separate loops ensures that the CPU and graphics cards have equal access to plenty of coolant, in the case of the graphics cards pre-chilled down to below room temperature.

The TEC controller also ensures that the TECs never have to work at 100 per cent load, and turn into hideously ineffective heatpumps. This means that when even hotter graphics cards make an appearance, the Gravistar will be well equipped to cool them and overclock the transistors off them. And by having two separate radiators, the Gravistar can cool its components more quietly than the Alienware, Real Machines or SavRow Dream PCs. And for the ultimate in 3D speed, Armari can also fit a pair of GeForce 7800 GTXs. Simply ask when you order.

• Cases - 21st November 2008
• Motherboards - 24th October 2008
• Gaming Headsets - 26th September 2008
• Dream PCs - 24th September 2008
• Headphones - 12th September 2008
• Media PC components - 22nd August 2008
• PSUs - 14th July 2008

• Western Digital Caviar Black 1TB - Hard disks / storage
• Asus EAH4870 TOP - Graphics cards
• Creative Sound Blaster X-Fi Titanium Fatal1ty Pro - Sound cards
• Multiwinia - Games
• Zotac GeForce GTX 260² - Graphics cards
• Sapphire Radeon HD 4850 X2 - Graphics cards
• Scan 3XS X58 Core i7 - Desktop PCs