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AMD's Super Bypass - AMD Improves their 750 Chipset


It is clear that AMD's "Super Bypass" feature provides substantial performance improvement. However, it really bothers me that there is no physical way to determine if a motherboard is outfitted with the new north bridge that supports super bypass. Even if a utility existed which would read back the special super bypass registers, most computer shops would probably frown if you asked them to setup the platform so you could run the program. If you were planning on ordering through the net or catalog you wouldn't even have that option. This gives me the impression that AMD was trying to hide this transition to super bypass. Why? I think AMD was looking to cover some of the performance loss due to the external cache becoming an issue. Keep in mind that AMD had to move to a divisor of more than 2 for the core clock/L2 cache clock ratio in Athlon processors of above 650 MHz, because there isn't a cost effective cache solution that will reliably run above 300 MHz. Changing the divisor naturally resulted in a performance loss. This isn't good news with Intel's Coppermine already nipping at AMD's heels. Super bypass is a blessing because it more than balances out the losses they took from moving to the new cache setting. Why do you need to keep something like this so quiet? Well, there are thousands of non-super bypass chipsets out there that aren't sold yet. Who would want a non-super bypass if they knew about it? The results could be that the chipsets (and motherboards) without super bypass would become much more difficult to sell. It would be better to secretly insert this new feature and as soon as the old chipsets are flushed from inventories, begin talking about super bypass. This is just a theory of mine but it makes perfect sense to me.

Looking at the performance benefit the Athlon platform gains when removing some of the memory latencies makes me anxious to see what the next generation chipsets will have to offer, such as VIA's KX133 Athlon chipset. Given that the AMD's 750 chipset is quickly falling behind the times with their 800 MB/sec memory throughput and 532 MB/s AGP 2X performance, VIA's new chipset should breathe even more performance into the Athlon platform. The KX133 will offer 4X AGP (>1 GB/sec) and a 133 MHz memory interface (<1 GB/sec). It's important to remember that the motherboards chipset is every bit as important in regards to performance as the CPU itself.