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Assembly, Overclocking, And Core Unlocking

System Builder Marathon, June 2010: $1,000 Enthusiast PC

Assembly went without a hitch on the hardware side of things, but the software installation wasn’t quite as smooth.

It seemed that Gigabyte's Radeon HD 5830 cards weren’t happy with AMD's general-purpose Catalyst 10.4 drivers and required older release candidate drivers on the bundled driver CD to be properly detected by Windows. Fortunately, the new Catalyst 10.5 drivers were released during our testing, and these seem to work with the Gigabyte cards. So, we used the newer drivers for our benchmarks.

Even so, we did bump into a problem with one of our game tests, S.T.A.L.K.E.R.: Call of Pripyat. This benchmark simply will not run on this system with both Gigabyte Radeon HD 5830 graphics cards installed. Turning CrossFire off in the drivers helps, but the benchmark continues to crash until the second card is physically removed from the system. This isn’t something we’ve experienced with S.T.A.L.K.E.R.: Call of Pripyat in the past, so it’s a bit baffling.

After a little online investigation, we noticed that other people have problems with Gigabyte's Radeon HD 5830 and S.T.A.L.K.E.R.: Call of Pripyat as well. We hope it's a driver issue that can be worked out in the future.

Overclocking and Core Unlocking

Since our CPU comes from a generic Newegg order (it's not cherry-picked by the manufacturer), unlocking the fourth dormant CPU core is fair game for the purposes of this comparison. If successful, this will turn our Phenom II X3 CPU into a Phenom II X4, allowing the $1,000 system to be a lot more competitive in multi-threaded application benchmarks.

The MSI 790X-G45 motherboard allows core unlocking through a simple Unlock CPU Core option in the BIOS menu. Flicking the switch rewarded us with a fully functioning quad-core CPU, and after proving this with some tests, we moved onto overclocking.

It's hard to complain after modifying this sub-$100 CPU into a fully functional Phenom II X4, but our overclocking efforts didn’t pan out as well as we hoped. With the CPU voltage upped to 1.5V and the northbridge increased to 1.26V, our maximum overclock was 3,424 MHz. The unlocked multiplier didn't help us all that much in this case, and our highest overclock employed a 16x multiplier coupled with a 214 MHz bus speed.

While the overclocked CPU ran 624 MHz above the stock setting, our final result was only 24 MHz faster than a stock Phenom II X4 965. Then again, we're not sure any other sub-$100 CPU would have been a better choice. An Athlon II X3 440 might overclock a few hundred MHz higher, but might not core unlock at all, leaving us without that fat 6MB of L3 cache. As it is, we think this overclock will at least get us within arm's length of the stock $1,500 system's numbers from our last SBM.

Our Gigabyte Radeon HD 5830 graphics cards weren't particularly overclock-friendly in a CrossFire configuration, delivering a meek 20 MHz core overclock (820 MHz total) and a more respectable 100 MHz (1,100 MHz total/4,400 MHz effective) memory overclock. When we ran them independently, we managed to squeeze higher clock rates out of these cards (in the 875 MHz core/1,150 MHz memory range), but these higher clock speeds didn't work when the cards were paired up in CrossFire.

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