Iwill KK266 Socket-A KT133A ATX

Breaking the Barrier

With the new Mushkin High Performance Rev. 3 memory, at CAS 2 and fast memory settings, we were able to hit 154MHz FSB without a hitch. Note that this is already 16% over the official 133MHz rating - much higher than the KT133 chipset ever achieved in terms of percentages.

By lowering the CAS latency to 3 and reducing other memory settings, we finally hit a wall at 161MHz FSB. At 161MHz, the system was still stable and we were able to run Content Creation Winstone 2000, SYSMark 2000, and Quake III Arena without any problems. At a speed of 162MHz, the system didn't even boot and a BIOS error appeared while booting. At a speed of 161MHz, that's more than 21% over the rated 133MHz.

The question now is whether this is the true FSB speed limit of the KT133A or we are still dealing with some other bottleneck? For starters, the heat generated by the North Bridge could be devastating As we found out in the ABIT KT7A-RAID review, at speeds of 137MHz and higher, a heatsink is required for stable operation. We have seen in the MSI K7T Turbo review that at a FSB speed of around 150MHz, a heatsink is still capable of cooling the North Bridge. However, at FSB speeds of 160MHz and higher, it is questionable whether the simple heatsink of the KK266 is enough to cool down the North Bridge.

Further, the memory would also be the bottleneck once again. Keep in mind that the memory chips are PC133 and were designed to run at 133MHz, and it is only by carefully handpicking the memory that it is able to run at 150MHz CAS2. Therefore we can't really expect the memory to do much higher, even with slower memory settings.

In order to eliminate the chance of the North Bridge generating too much heat, we replace the heatsink on the KK266 with the HSF unit that we took off from the EPoX 8KTA3. To our surprise, the system booted up and ran flawlessly at 162MHz FSB, able to knock down all the benchmark tests. This proves that the heat generated by the North Bridge may become the bottleneck for overclocking the FSB beyond 160MHz.

The North Bridge of the Iwill K266, covered here by the HSF unit from the EPoX 8KTA3

The fan connector of the HSF was not designed for the fan connectors on the KK266, but a little elbow grease did the trick

Unfortunately, at 163MHz, the system always froze at the boot up screen. Since we don't have any other memory that's capable of 160MHz and higher, we weren't able to determine if the Mushkin SDRAM we used has hit the wall or it's actually the FSB limit.

Here we really see the potential of the Mushkin High Performance Rev. 3 SDRAM. It simply takes away the memory bottleneck from the system and allows users to truly unleash the power of the KT133A chipset. On the other hand, we also see the incredible potential of the KT133A chipset, being able to overclock by more than 20% , compared to the meager 10% of the KT133 chipset.

The Bad

It would be great if Iwill had included the USB cable needed to take advantage of the second USB root hub right out of the box.

The CPU socket is too close to the right edge of the motherboard, which might pose a problem when trying to change the CPU after the motherboard has been mounted inside a case.

USB Compatibility

• Number of Front Universal Serial Bus Root Ports: 2
• Number of Rear Universal Serial Bus Root Ports: 2
• USB IRQ Enable/Disable in BIOS: Yes
• USB Keyboard Support in BIOS: Yes

Recommended SDRAM

Recommended SDRAM: 1 x 128MB Corsair PC133 SDRAM; 1 x 128MB Mushkin PC133 SDRAM

SDRAM Tested: 1 x 128MB Mushkin PC133 SDRAM

Manufacturer: Corsair
Purchase Website: http://www.corsairmicro.com

Manufacturer: Mushkin
Purchase Website: http://www.mushkin.com