Tom's SBM: The $1,500 Mainstream PC

Assembly & Overclocking

We were lucky this time; the build went off without a single hitch. We did invest some time into installing Swiftech’s H20-220—it wasn’t difficult, but you want to take your time when installing and testing liquid cooling.

With no leaks to fry our mainstream build, the system booted up straight away. Setting up RAID 0 was as easy as setting the option in the BIOS; the Vista install took over from there. After some testing, it was clear that the system was a strong performer for the price; so we ran the standard benchmarks and proceeded to overclock.


As we stated before, while our old Q6600 sample provided us decent but not awe-inspiring results in our last system builder marathon. We wanted to get our hands on a new Q6600 revision G0 sample to really see what these processors can do, before moving on.

With the H20-220 water-cooling system keeping temperatures low, we started by simply boosting the CPU voltage to 1.5 V, and increasing the front side bus speed from the stock 266 MHz to 400 MHz. These changes increased the CPU speed from 2.4 GHz to 3.6 GHz straight away.

To our glee, the system booted immediately and took us right to Windows. Everything seemed peachy until we ran the Prime95 stress test, which failed at about 18 minutes in. We played with the BIOS voltages, memory timings, memory speeds, and other settings, to no avail. Regardless of how willing it was to work in Windows, the CPU was not stable at 3.6 GHz. So much for our dreams of exceeding 3.7 GHz.

At the end of the day, we were forced to pull back to 3.456 GHz at an FSB of 384 to achieve total CPU stability. While this is an impressive 1 GHz faster than the stock speed of the Q6600—and will provide a massive gain in performance over that default—we have to admit that it’s time to look to other CPUs to reliably support higher overclocks. The E8400 may not share the Q6600’s four cores, but it will likely make it to speeds approaching 4 GHz; the higher speed will compensate well for the fewer cores, and two processor cores are the sweet spot for which most software is optimized anyway.

As for our Radeon 4850 graphics cards, the overclocks there were just as disappointing. The strange part was that the Catalyst Overdrive feature—which we usually find to be conservative—would validate the cards at an impressive 785 MHz GPU speed. However, using these speeds would crash the system once the Crysis benchmark was run.

We settled with a stable 700 MHz core and 1070 MHz memory overclock. This is not bad compared to a reference Radeon 4850’s core clock speed of 625 MHz, but not great considering these cards were already factory overclocked to 685 MHz out of the box.

  • Hi,
    This is my first comment although I have reading this website for the past 8 years. Anyway to th point - Usuallt I agree 90% with you on components you choose, especially in the high-end and budget configuration. But this time a lot of tings strikes me: First it is the CPU - I am pleased You have addressed the issue to a great degree in the article later, but still I think it will be appropriate to try to further increase the voltage because this is a watercooled 65nm CPU; Second the chipset I think it`s ot the best choise, X38 is a former high-end chipset so when You`re overclocking you should get the faster binned X48, but because this is mid-range configuration I think it`s best to taka advantage of the super popular P45; Third the motherboard I am not sure if a motherboard with a not so stron PWM is the best tool for overclocking such a power-hungry chip, You should try to overclock on a different motherboard to see why are yuo`re not receiving a more descent overclock;Forth and last the price difference to a 1066MHz kit is pretty small so I think it`s preferable because tis will give You flexibility to try higher FSB with lower multiplier, wchich should give another notch of performance. I am saying all this because I want to help You make this website even better.
    Best Regards. Bobby
  • I think it would be interesting to see power consumption and noise benchmarks for the PCs you build in this article series.
  • JeanLuc
    I can see why you wanted to use a water cooling kit so that you got the best possible overclock from the CPU but water cooling is hardly ‘mainstream’ which is what I thought this system builder marathon was all about. The same goes for the choice of motherboard, the X38 is an enthusiast’s motherboard, something like the Biostar T Power i45 would have been more appropriate and according to CustomPC UK is just as good at overclocking as any other motherboard.

    Good choice in video cards, I’m glad you didn’t choose 4850’s with the stock coolers because those bad boys run really hot.
  • Proximon
    Well it was a good try. Would have preferred a more truly mainstream rig, but then the forums are full of those.
  • Malovane
    And I thought a $400 Dell or E-Machine was mainstream..
  • fallen2004
    P45 wouldnt have workd cos it would bottleneck the crossfire as it only runs at 8x and 4850's need 16x
  • neiroatopelcc
    JeanLucI can see why you wanted to use a water cooling kit so that you got the best possible overclock from the CPU but water cooling is hardly ‘mainstream’ which is what I thought this system builder marathon was all about.
    I agree with this dude really. Anything watercooled is enthusiast, not mainstream. I don't know if americans just treat themselves to better hardware, but here in europe anyone with watercooling is considered an enthusiast. Nobody with a reasonable budget is going to 'waste' money on water cooling. Imo a tuniq, tr120 or a scythe something cooler would've been a more appropriate midrange guess. Also I'd expect anyone building a pc today to pick a p45 over an x38 (though I like the red slots on this one)
  • neiroatopelcc
    fallen2004P45 wouldnt have workd cos it would bottleneck the crossfire as it only runs at 8x and 4850's need 16xBtw I'm running a 4870 on an x16 pcie v1 - that equals an x8 pcie v2 connection. And I can hardly claim that my system's limited by the bandwidth.
  • dirtmountain
    A E8500, single socket P45, HD4870x2,Sunbeam core contact cooler and a Coolermaster 690 would have made their budget and blown the socks off that build.
  • grumps01
    How about some info on this "mainstream" system sound wise. How Loud or quite is this system use this Swiftech H20-220 Kit with larger pumps etc. Also what's the temperatures like (heat dissipation) like in general with this combination please?

    I know most ppl are probably more interested with the benchmarks, but I'm sure this might interest some people on what's it like to live with, thanks!