Gigabyte GA-7ZXR (Rev. 2.2) Socket-A KT133A ATX

Making up the Loss

When we looked at the original GA-7ZXR, it took quite a big hit for its lack of overclocking features and it didn’t help that the stability was not particularly impressive either.  At the time we did our roundup in November 2000, Gigabyte told us that they were working on a newer revision of the board, which would be quite different from the one we looked at, with more overclocking options.

When we received that message, we assumed that Gigabyte was referring to the “missing” multiplier ratio settings, which was present on most other KT133 boards.  However, when we finally received the current revision of the GA-7ZXR, we concluded that we were wrong, as Gigabyte had included lots more features than just multiplier controls.

For starters, and the critical multiplier adjustments are included, with ratios between 5 and 12.5 (in 0.5 increments), configured through a set of five dipswitches.  The setting is not available in the BIOS, but from our KT133A Chipset: the Issue article, we know that a dipswitch implementation is indeed very reliable.

Dipswitches for modifying the multiplier and I/O voltage

Like the original, there is another set of five dipswitches controlling the FSB speeds.  Using the set of dipswitches you can choose from 95 / 100 / 102 / 105 / 110 / 113 / 115 / 120 / 133 / 135 / 137 / 139 / 141 / 143 / 145 / 150 / 155 / 160 / 200 MHz.  Although this list is already much longer than the speeds available last time around, this time there’s also the option of adjusting the FSB right in the BIOS.                                                                                

The dipswitch block for setting the FSB speed

The way the BIOS settings work is dependant on the FSB speed set using the dipswitches.  If the FSB dipswitches are set between 95 and 100MHz, BIOS offers speeds between 100MHz and 120MHz in 1MHz increments.  On the other hand, if you set the dipswitches to 133MHz or higher, you will be able to choose any speed between 133MHz and 150MHz in the BIOS, also in 1MHz increments.  The inclusion of FSB speed adjustment in the BIOS is definitely nice, but it’s the new 1MHz implementation that truly puts the GA-7ZXR (2.2) among the top KT133A boards when it comes to overclocking.

Apart from multiplier ratio and FSB speed settings, voltage tweaks are another important factor for overclocking, and Gigabyte has covered this as well.  For CPU core voltage, you can select between 1.5V and 1.85V in 0.025V increments through a set of six dipswitches.  For I/O voltage, the GA-7ZXR (2.2) allows you to select between 3.3 / 3.4 / 3.5V using two dipswitches.  Furthermore, Gigabyte also decided to put in AGP voltage tweaks, allowing you to choose from 1.5 / 1.6 / 1.7V. 

The dipswitches for adjusting the CPU core and AGP voltages