System Builder Marathon, Sept. 2010: $2000 Performance PC

Overclocking

After trying various methods to overclock our AMD Phenom II X6 1055T processor without changing its multiplier, we decided to see how far its reference clock would go. Setting it to the highest-available VDD voltage, lowest memory ratio, and a low 10x multiplier, we found that a reference clock of 290 MHz was stable.

Next, we began increasing the CPU clock multiplier until we reached its 14x limit, and again found the CPU to be stable. Unfortunately, the system had trouble rebooting. Selecting a reference clock of 288 MHz solved the reboot issue.

With our CPU frequency limited mostly by its reference clock, we began backing down the VDD voltage until we found the lowest stable setting. While we were testing various CPU voltage levels, we increased our DRAM voltage and found that 1.60 V allowed a 1:2.66 DRAM ratio for a resulting DDR3-1533 data rate.

Using our intended 1.65 V memory voltage limit allowed our modules to be reduced to 7-7-6-20 timings, while retaining the high DDR3-1533 data rate. We think this combination of speed and timings is quite good for an 8 GB set of modules rated at DDR3-1333 CAS 9.

CPU-Z confirms our speeds and timings, with the CPU at 4028 MHz.

With our CPU and DRAM settings locked in through the BIOS and completely tested for stability, it was time to see how far our graphics cards could be pushed. While Nvidia System Tools allows clock and fan speeds to be set at a constant rate, MSI’s Afterburner utility adds advanced fan controls for automatic adjustment, eliminating the constant noise of high fan speeds when temperatures are relatively low.

While it’s possible to keep previously-set clock speeds without starting the utility at every boot, the utility must run constantly for our fan speed map to apply. Two settings allow the utility to start with windows while minimized to the task bar.

We increased the GeForce GTX 480 core clock from 700 to 816 MHz, and pushed its memory from GDDR5-3696 to GDDR5-4132. Stability was tested at an ambient temperature of 27° Celsius, and a cooler workspace would have allowed us to push for even higher clock speeds.

Thomas Soderstrom
Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.
  • IzzyCraft
    Love the case choice everything else is pretty much can't really hate it or love it, but i mean you can't really hate any of the parts when they cost that much as they are all good but some just not right for some jobs.
    I do not care for AMD and SLI just because you'll be using an nvidia chipset and my past experiences with them have been poor.
    I also do not care for 6 cores for games although i mostly use my computer for other things which may like those 6 cores, but i don't find too many uses for 2 480's outside of gaming.

    Hopefully the next one will be one i can't help but agree with, A i5-750/760 with 2 460's in sli :D
    Reply
  • Tamz_msc
    This month's SBM is forgettable.It confirms that AMD+SLI = BIG fail.
    Reply
  • Tamz_msc
    A better option( without sacrificing GTX 480 SLI) in my opinion is:
    Core i7 950 (add 100$)
    GIGABYTE GA-X58A-UD3R (add 50$)
    GSkill 6GB RAM(subtract 70$)
    Reply
  • proofhitter
    Big CPU fail. I love your honesty, good one Tom's! Nice try nevertheless. Keep it up!
    Reply
  • jrharbort
    The lesson here? AMD hexacores are still the best value on the market, but is still unable to keep up with the i7 in overall performance clock for clock. It's sadly not the best choice in high end systems, but it still wont stop me from recomending it to friends interested in sub-$1000 systems.
    Reply
  • sassan_88
    I dont like systems Based on AMD's chipset
    Reply
  • jj463rd
    With Sandybridge and Bulldozer just right around the corner I don't think that it makes any sense to build right now with current (especially CPU + motherboard)components.
    Reply
  • Crashman
    jj463rdWith Sandybridge and Bulldozer just right around the corner I don't think that it makes any sense to build right now with current (especially CPU + motherboard)components.Maybe not...this system was built a couple months ago.
    Reply
  • makwy2
    Love the honesty. I think this is just shows that a MUCH cheaper AMD chip ($700 less) is close but not quite in true competition with the top of the line Intel chip. I'll stick to my AMD chips because I am not made of money.

    Again, I love the honesty and straight talk TH brings with these bi-monthly features that give system builders a real idea about performance and cost-effective parts.
    Reply
  • aaron92
    I really do value the AMD Hex vs Intel, 6 cores is already cutting edge and 12 threads is going beyond a desktop computer for this year atleast.
    Reply