760 has arrived!
As AMD's launch partner for the 760 chipset, Gigabyte is the first motherboard manufacturer to bring a fully-fledged 760 product to market. In particular, the GA-7DXC motherboard we're reviewing today.
With the added memory bandwidth its DDR SDRAM provides, many hardware enthusiasts have been looking forward to the 760 chipset the GA-7DXC is based on. One quick glance over the GA-7DXC spec sheet however, reveals one missing ingredient: support for PC2100 and the new 266MHz front side bus. Is this missing feature only a minor kink in the GA-7DXC's performance, or is it the GA-7DXC's Achilles Heel? This is something we'll attempt to determine over the course of this review.
What happened to 266?
The first question you're probably asking is how the GA-7DXC is based on the 760 chipset yet doesn't support all its features. The answer revolves around the 760 chipset and an oversight by Gigabyte. Due to insufficient filtering, noise from the 761 North Bridge can generate a clock glitch into the CPU, causing the system to hang. At 200MHz the GA-7DXC runs fine, but at 266MHz the GA-7DXC needs an external circuit to filter out the additional noise. This circuit is provided in the GA-7DX (the follow-up to the GA-7DXC), but not in the GA-7DXC.
Therefore, running the front side bus at 266MHz on the GA-7DXC is officially considered overclocking. For those of you who read our KT7A-RAID review, the GA-7DXC used was running at 266MHz (9.0x133).
In case you were wondering, 266MHz Athlons function properly on the GA-7DXC, but will only be operating at 200MHz.
By not implementing the circuit in the GA-7DXC design, Gigabyte has been able to get the board to market quickly. For instance, our evaluation board arrived over the Christmas holidays; production GA-7DXC's hit retail shelves in early January. While the GA-7DXC is only a PC1600 solution, the GA-7DXC has given Gigabyte approximately three weeks of lead-time over its closest competitors, ASUS and FIC. Volume shipments to the US from both manufacturers have recently just begun (ASUS two weeks ago and FIC just last week).
Does the added memory bandwidth allow the GA-7DXC to outpace KT133? And how does this motherboard stack up against the newer KT133A chipset? Those were the questions we set out to answer, but first let's discuss some of the GA-7DXC's features.