Features/Overclocking

Hasn't 1.2GHz been released?

If you've checked Price Watch recently, you'd think that the 1.2GHz Athlon is nothing new -- the processor has been listed on their page for a few weeks now. Taking a page from Intel, AMD has been supplying OEM, reseller, and retail channels with the processor for a few weeks now. Chances are you still won't be able to pick one up at your local computer store, but 1.2GHz parts are out there. Prices currently listed on Price Watch have the 1.2GHz Athlon starting at under $500!

Keep in mind that a listing on Price Watch doesn't guarantee availability. Some vendors have been known to list processors on the site at a competitive price well in advance of actually receiving sufficient supply. By the time the vendor has the processor in stock, prices have dropped, making what was once a great buy, merely an average purchase. When dealing with Price Watch, we heartily recommend calling in advance, along with checking vendor-rating sites such as BizRate.com and Reseller Ratings.

First Impressions

Like previous Thunderbird processors, the 1.2GHz Athlon contains 256K of L2 cache running at the same speed as the processor core. Both the front side bus (100MHz) and core voltage have remained the same (1.75V). The only variable that has changed is the clock multiplier, now at 12.0x.

For more details on the Thunderbird's specifications, check out our preview from June, but for now here's a quick list of the processors' features:

Socket A interface
0.18-micron manufacturing process
37 million transistors on a 120mm^2 die
128K L1 cache, 256K full-speed L2 cache
Fully-pipelined, superscalar floating point engine
200MHz system bus
Enhanced 3DNow! Instructions

Later this year, AMD plans to raise the system bus to 266MHz as well as add support for double data rate memory via their upcoming 760 chipset. We'll provide more information on 760 near its release. Both additions should provide a noticeable improvement in memory and system bandwidth, allowing the Athlon to compete more favorably with Pentium 4.

Overclocking

Despite some reports that have been posted on the Web, AMD hasn't removed pins from the bottom of the CPU -- unlocking the processor via the L1 bridges is still possible, and is the method we used to unlock our processor.

With the L1 bridges connected and the CPU mounted in our ABIT KT7-RAID motherboard, we proceeded to overclock. With our 1.1GHz Athlon, we maxed out at 1.224GHz, so we were initially skeptical of how successful our overclocking attempts would be.

Fortunately, this initial skepticism was incorrect, at 1.25GHz (the maximum multiplier supported by the KT7-RAID), the CPU ran through repeated loops of 3DMark 2000 and Quake III: Arena without a single lockup. With our multiplier options exhausted, we slowly cranked up the bus speed. After repeated attempts to stabilize the system at 106MHz FSB, we finally had to settle on 1313MHz (12.5x105). At that clock speed, we needed to supply the core with 1.825V (another beauty of the KT7-RAID, its 0.025V increments) to run completely stable.

We feel we would have been able to run the system at even higher clock speeds had we used a more exotic cooling solution. Temperatures at 1313MHz were in the mid 120's (in degrees Fahrenheit).