And the chip that our AMD lovers really love right now is the Thoroughbred B version of the Athlon XP.
Atomic has been harping on about the overclocking headroom of Intel CPUs quite a bit over the last year. So much so that our AMD fans are feeling a little left out in the cold. And the chip that our AMD lovers really love right now is the Thoroughbred B version of the Athlon XP.
Identifying one of these processors is a little trickier than ID'ing the stepping of an Intel CPU. To make sure you have a Thoroughbred B Athlon XP, check the ordering code of the CPU (usually found on the Website of most reputable retailers). The Thoroughbred B has an ordering code of AXDA1800DUT3C. But the fun doesn't stop here, as there are two grades of Tbred B: low grade and high grade. The high grade promises the most potential for overclocking; unfortunately these aren't currently available in Australia in the 1800+ speed, at least according to Compucon, www.compucon.com.au, the very kind supplier of our review Tbred B. Now you know of at least one retailer who understands CPU steppings.
To tell what grade your Tbred B is, look at the second line of the processor code - if it begins with A it's a high end, while J is for the low end. The lowest speed Tbred B that you'll find is the 1700+, but these are being phased out so they'll soon be rare, which is why we tested with the 1800+. Could the 1800+ impress us anywhere near as much as the free performance boosts we've been wringing out the P4? Not quite. The 1800+ runs at a default speed of 1.53GHz with a voltage of 1.6V. AMD appears to have given up on the trenches between the L1 bridges, so the old pencil trick allowed us to fudge with the multiplier without worrying about stressing the rest of our system. We managed to increase the multiplier from its default of 11.5 up to 14, and tweaked the FSB on our AT7 MAX2 up to 140MHz to get the CPU running at its maximum stable speed of 1960GHz. It was necessary to increase the CPU voltage up to 1.85V to maintain this speed. We gave it a quick run through 3DMark2003's CPU test to see the kind of performance gain you could expect from such an overclock. At default speed it scored 378 CPU points, while at the overclocked speed it scored 436.
This is an overclock of around 28%, lifting it to the speed of the Athlon XP 2400+, which would normally set you back around $300. Considering you'll only pay around $170 for the 1800+, this is a very nice saving in cash. Sadly for AMD, it's still not quite as impressive as the 50% overclocks that many C1 Pentium 4 owners are getting, but it is great value for the cash strapped gamer.
Issue: 133 | February, 2012