Overclocking
Overclocking
With the ABIT NF7-S nForce2 motherboard kindly allowing me to choose any multiplier I wished, I simply chose a higher multiplier of 14x and tried to boot successfully into a fresh installation of Windows XP Professional. The CPU duly obliged, giving a running speed of 1869MHz (14 x 133.5FSB), all at 1.5v VCore. Things were looking up. We'd already jumped up from an XP1700 to a pseudo XP2200. Raising the FSB by 5MHz at a time, I tried to see just how high this XP1700 JIUHB could go on default voltage. 2GHz came and went (XP2400 speeds) and, surprisingly, 2.1GHz seemed fine, too. We had exceeded the basis specification of the XP2600 (166FSB) CPU with only 1.5v VCore. It seemed as if all the code deciphering on the previous page had made some sense.
Default voltage operation hit a stable ceiling at @ 2130MHz. A 650MHz overclock without adding more gas to the mix. The CPU-Z screenshot below detailed the prodigious potential of this CPU.
Raising the Vcore to a sensible 1.7v in BIOS resulted in a Windows' load voltage of ~ 1.65v. This time, however, the overclock was approached with an enthusiast's point of view. Any self-respecting enthusiast in possession of a decent nForce2 motherboard considers 200FSB to be a reasonable, performance-based FSB target. One must have a motherboard that's capable of this currently unsupported FSB, and have system memory, preferably in dual channel mode with low latencies, that can provide the necessary oomph.
After a few minutes spent fine-tuning the BIOS, the XP1700 JIUHB, ABIT NF7-S, and 2 x 256MB Mushkin EMS PC3500 combination successfully booted into Windows at 2305MHz / 200FSB / dual channel memory with 2-6-2-2 timings, all with just 1.65v CPU voltage, 1.7v chipset voltage, and 2.7v DDR voltage. Lovely.
Well over 800MHz above default speeds and only 1.65v CPU voltage. Can you say impressive ?. Lots of raw MHz, coupled with a high FSB, and masses of low latency bandwidth. This combination should turn into something of a benchmarking monster. However, setting the ABIT's VCore to a maximum of 1.85v (around 1.78v under load) only resulted in an additional 100MHz clock speed.
Just to reiterate the test setup.
AMD XP1700 at default speeds of 1470MHz* / 133FSB / dual channel Mushkin PC3500 at 133MHz, 2-6-2-2 timings
AMD XP1700 at overclocked speeds of 2305MHz* / 200FSB / dual channel Mushkin PC3500 at 200MHz, 2-6-2-2 timings
AMD XP1700 at XP2700 default speeds of 2171MHz* / 166FSB / dual channel Mushkin PC3500 at 166MHz, 2-6-2-2 timings
*As the test ABIT NF7-S slightly overclocks the FSB at each setting, the actual MHz is a little higher than expected.
We'll see just what kind of benchmark improvement we receive from running a comparatively slow system (stock) against a highly-tuned offering (overclocked). The vastly more expensive XP2700's performance should be a decent yardstick to measure our success against.
