Overclocking: ATI Bullhead

ATI has some stiff competition from nVidia in the Athlon 64 Enthusiast market. nVidia is well known and trusted by AMD enthusiasts who know the nForce3 Ultra and nForce4 will provide the kind of extra performance they are looking for.

Move over, nVidia, because the ATI Reference board reached an amazing 283x10 at 4X HyperTransport and 2.5-3-3-10 memory timings.

Front Side Bus Overclocking Testbed
Default Voltage
Processor: Athlon 64 FX55
CPU Voltage: 1.5V (default)
Cooling: Thermaltake Silent Boost K8 Heatsink/Fan
Power Supply: OCZ Power Stream 520W
Memory: OCZ PC3200 EL Platinum Rev. 2
Hard Drive: Seagate 120MB PATA (IDE) 8MB Cache
Maximum OC:
(Standard Ratio)
224x13, 2912MHz (+12%), 1:1 DC Mode,
2-2-2-10 memory timings, 5X HT, 2.6V
Maximum FSB:
(Lower Ratio)
283 x 10 (2813MHz), 2 dimms, 1:1 DC mode,
2.5-3-3-10 1T memory timings, 4X HT, 2.85V

Using Hynix Rev. B double-sided memory, we were also able to reach a 291 (DDR582) overclock, matching the highest overclock that we have ever achieved in testing with DS DIMMs in Dual-Channel mode. The timings and bandwidth were lower at 291, which also required 2X HT, since 3X was not an option in the ATI RX480 BIOS. ATI tells us that 3X will be implemented in production BIOS for the Bullhead board. 283x10 at 2.5-3-3-10 gave the highest memory bandwidth available on the ATI with our standard overclocking test setup.

Intrigued by the performance of double-sided DIMMs in dual-channel mode, we asked ATI about the highest performance dual-channel overclocking that they had achieved with the RX480 in their labs. ATI shared results and timings using 2 single-sided 256MB PQI DIMMs at 2.5-4-4-9 1T timings, at a frequency of 313 or DDR616. We did not have single-sided Hynix B DIMMs in the lab to try to duplicate ATI's test setup. However, based on our results with DS DIMMs, we have no reason to doubt their results. If you compare these overclocks to the outstanding overclocking capabilities that we found with the DFI LANParty UT nF3-250Gb, you will see that the ATI Bullhead is reaching further in Dual-Channel mode than the highest clock speed that we could reach in single-channel mode on the Socket 754 DFI.

In our opinion, ATI has more than succeeded in their goal of proving to computer enthusiasts that the RX480 is a chipset for serious performance overclocking. These are, overall, the best overclocking results that we have ever seen with an Athlon 64 motherboard. The fact that these were achieved on a Reference board is all the more amazing!

Front Side Bus Stress Test Results:

As part of our overclocking tests, a full range of stress tests and benchmarks were run to make certain that the ATI RX480 Bullhead was stable at each overclocked FSB speed. This included Prime95 torture tests and the addition of other tasks while Prime95 was running in the background. Many motherboards reach high overclocks and then behave as if they are on the ragged edge at those high overclocks. The ATI Bullhead was remarkably stable at both 224x13 (CPU Limited) and the even more challenging 283x10. For maximum stability at both settings, we needed a modest increase in CPU voltage to 1.55V, but at that setting, we were able to loop benchmarks for several hours without a system failure.

BIOS Features: ATI Bullhead Memory Stress Testing: ATI Bullhead


View All Comments

  • flatblastard - Saturday, April 9, 2005 - link

    Hmmmm, still no real availability even now...Looks like MSI may be our only chance at this chipset....what as bummer :( Reply
  • philpoe - Sunday, February 20, 2005 - link

    Hmmm, after no real availability (in the US at least) as of Friday 2/18/05, there's suddenly a slew of shops selling the MSI board on pricewatch, including Newegg. Anyone know of a reason why the boards are so slow to trickle out? Reply
  • philpoe - Monday, February 7, 2005 - link

    Is it possible to purchase these reference boards? I seem to see them in retail-looking packages in reviews from Canada.
    If you can get your hands on one, are the BIOSes available to the public, or only to the select HW review sites?
  • Wesley Fink - Thursday, November 11, 2004 - link


    We have added the following update to p.6:

    "UPDATE 11/11/2004: ATI has provided an updated BIOS which corrects the issues of 333 timings with 4 double-sided dimms. With the new BIOS we were able to run 4X512MB DS OCZ 3200 Platinum Rev.2 at 2-2-2-10 timings at DDR400 with a 2T Command Rate. This performance matches the best we have seen with 4 DS dimms on an Athlon 64 motherboard."
  • Momental - Wednesday, November 10, 2004 - link

    #35: I'm right there with ya, bud. Just when I "think" I've made up my mind to do the complete overhaul, the next exit appears on the highway taking me that much closer to the "Best Soft Serve in Town"!!

    The ol' gut tells me to hold out until some time just after the ball drops in Times Square and we'll all be in Fat City, so to speak. ;)
  • callius - Tuesday, November 9, 2004 - link

    Somewhat OT maybe:

    anyone seeing a reason that the next rev of A64 supporting SSE3 (in market Q1/05) coul not be plugged in a 939-mobo (nvid, ati or via) without problems (except any necessary BIOS update) ?

  • callius - Tuesday, November 9, 2004 - link

    Only minus vs nforce4 is that the SB does not support SATA-II's NCQ (for Seagate's upcoming 7200.8 series). Maybe with next SB in Q1/05 though ??? Reply
  • mlittl3 - Tuesday, November 9, 2004 - link

    Completely off topic, but does anyone know why there are four chipsets (two actively cooled, one passively cooled and the other with no cooling) in the SLI Tyan motherboard that #33 gave a link for? Reply
  • xeper - Tuesday, November 9, 2004 - link

    i can't seem to find ANY mention whatsoever of shared memory allocation. can someone help me out here? Reply
  • nserra - Tuesday, November 9, 2004 - link

    Isn’t this very funny, I mean Ati was a very close partner to Intel, and they now bring to intel its one competition product but for the intel competitor.

    I see now no reason for Dell or other companies go for intel, because really intel had (has) the edge with integrated solutions.

    A "part" I thought that there weren’t AMD IGP chipsets because it wasn’t possible to use the integrated memory controller for graphics, at least until AMD64 rev E0 came out?

    If ati is going amd on pcie first, these shows that amd have the best processor and will continue for the time been. Even dothan can do much to turn it around again to intel side. And i bet that new p4 2mb is still with problems (performance, heat, …) and every one is running away from intel because already know this even intel, bringing dothan to the desktop market.

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