Product Listing

Foxconn C51XEM2AA (nForce 590 SLI)

By Zachary Chan - 25 May 2006

Overclocking

Overclocking

It's been a while since overclocking has gotten a section of its own, but the nForce 590 SLI has proven to warrant it. The C51XEM2AA comes with a truckload of overclocking options that will make even some of the most jaded enthusiasts jump for joy. Sure, we've mentioned it time and again that the board fully follows NVIDIA's design, but NVIDIA is now in their "show off" mode so all of the advanced functions are enabled in the C51XEM2AA's BIOS. The following list details the frequency and voltage options available:-

  • FSB (CPU HT) Frequency: 100MHz to 500MHz (in 2MHz steps)
  • MCP-SPP HT Frequency: 200MHz to 210MHz (in 0.5MHz steps), 210 to 230MHz (in 1MHz steps), 230MHz to 500MHz (in 2MHz steps)
  • HTT Multiplier (CPU-SPP/SPP-MCP/MCP-SPP): 1x to 5x
  • PCIe x16 Frequency: 100MHz to 200MHz (dual independent slots)
  • RAM Frequency: DDR2-400, DDR2-533, DDR2-667, DDR2-800
  • CPU Voltage Settings: 0.3750V to 1.8500V (in 0.0250V steps)
  • Memory Voltage Settings: 1.825V to 2.500V (in 0.0250V steps)
  • HT CPU-SPP Voltage: 1.225V to 1.400V (in 0.0250V steps)
  • HT SPP-MCP Voltage: 1.325V to 1.500V (in 0.0250V steps)
  • SPP Voltage: 1.25V to 1.40V (in 0.050V steps)
  • MCP Voltage: 1.525V to 1.700V (in 0.0250V steps)
  • Multiplier Selection: Yes (unlocked CPUs only)

Even the frequency settings panel is very detailed with independent buses for HT and PCI Express.

Part of the extensive memory timings available.

Our previous experience with nForce4 based motherboards have never yielded very good overclockability with a full 5x HT multiplier. However, the C51XEM2AA was a different beast altogether. As per our usual practice, the CPU and memory frequencies were first down-clocked so that they are kept within safe settings and do not become a factor in overclockability. We then tried to push the CPU HT link as far as we can in a no holds barred approach, increasing HT link and chipset voltage as necessary.

We managed to coax the C51XEM2AA up to 314MHz completely stable by pushing both the SPP and CPU HT link voltage to 1.4V. Now, remember that this is still at a full 5x HT multiplier, so the total HT link is now running around 1570MHz providing a theoretical 12.5Gbps bandwidth, a 57% boost over the default 1000MHz (8.0Gbps) link.

Sadly though, lowering the HT multiplier within the BIOS didn't make any difference to overclockability. Setting the HT multiplier to 4x or even 3x didn't gain us any additional increase as the board seemed to be stuck at the 314-316MHz range no matter what we tried. Interestingly however, we did manage to push the board a little higher using NVIDIA's nTune software under Windows. While the BIOS would no longer budge, nTune was able to push the board up to 330MHz at HTT 4x. However, if you do the math, 330*4 will give you an approximately 1320MHz HT link, which is still lower than the total bandwidth at HTT 5x.

*Max FSB @ HTT 4x was only achieved with NVIDIA's nTune software.

nTune monitoring tool, shows our overclocked HT link bandwidth and voltages.

CPU-Z showing the running HT bus speed.

Considering how flexible the nForce 590 SLI chipset seemed to be, we also tried to overclock the MCP-SPP HT link further than what LinkBoost would allow and we also managed to hit 300MHz there easily at HTT 5x.

LinkBoost pushes the clocks 25%. We found out that even a 50% boost will work flawlessly too.

NVIDIA has been touting higher overclockability with their flagship nForce 590 SLI chipset and we were actually very impressed with what the C51XEM2AA was able to achieve, though it is evident that Foxconn still needs to work on the BIOS. We're more than excited as to the full capabilities of the nForce 590 SLI.

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