Xabre 400 Roundup - August 2002
Gigabyte SP64D-H
The SiS Xabre chip has attracted attention of the most named eminent brands, among them the reputable Gigabyte. That companypresented their video card SP64D-H. Here at 3DNews we received an OEM version of this card which came in a Radeon7500 package turned inside out, so we can't yet say anything certain about the final shipment of Xabre from Gigabyte.
Although the video card itself looked similar to the reference, there are numerous differences. But first, the general features. As other boards in our review, Gigabyte SP64D-H also has 64 MB DDR SDRAM onboard. There is a DVI-out and a TV-out on the board.
The video card is made on a red PCB. Upon a closer look it becomes clear that Gigabyte engineers took much care of their first video card based on the new SiS chip. That is best seen on the board panel. The DVI-out is the same as on the SiS-based video card, the S-Video connector here has seven pins instead of four, and the S-Video cable can be easily plugged to it, so can the adapter S-Video - Composite.
Use of the DVI-out forced us to install a SiS301 chip of MV version on the video card, as is the case for the SiS reference board.
This videocard from Gigabyte has no jumpers, so switching between AGP modes and image display on the TV will be effected either automatically or via drivers. Since the drivers to Xabre chips are rather poorly made currently, the user might not be able to make the card run at the AGP 8x mode or output a signal in the needed format whenever necessary.
The remarkable feature of the video card from Gigabyte are those two cooler sockets. They are mounted at the edge of the video card, close to its power supply unit. Both sockets have 3 pins each and are marked as AN1 and AN2. A question is why the video card need two coolers? And, if the cooler is hooked up with 3 wires, why don't the drivers provide an opportunity to read the rotational speeds?
Of course, there is the only one cooler installed on the Xabre400 chip. That is a plainaluminium cooler, small insize, with thick ribs. It resides on a thermal pad, so the cooling is not as good as it could be provided thermopaste were used instead. The cooler has an integrated rotational speed sensor, but its readings are accessible only through drivers modified by Gigabyte - the reference driver has no tab to do with that.
A Xabre400 graphics chip is hidden under the cooler. The chip has the same revision A1 as in other video cards but was produced later, so its surface is not mirror-like as other video cards in our review, but mat. Frankly, it's not a big deal what surface is inside. What matters is the overclocking results.
The video memory on board is made up of eight DDR SDRAM chips installed along the both sides of the video card one upon another. Instead of standard EtronTech memory module having 3. 3 ns cycle time that is used on most video cards with the Xabre400 chips, here we used a 4 ns Hynix module. I wouldn't dare say which memory is cheaper or better, but the 4 ns memory at Gigabyte SP64D-H runs at its rated clock frequency - 500 MHz, so the overclocking may be problematic. On the other hand, Hynix is a reputable brand. So let's see.
Overclocking
The rated clock frequencies of Gigabyte SP64D-H are still the same: 250/250(500) MHz The first thing of interest to us was the memory overcloking. Both previous video cards with the EtronTech 3. 3 ns memory successfully overclocked up to 270(540) MHz. So from that video card we expected any different results - no matter higher or lower, but different. It was a great surprise for us to know that the memory wouldn't overclock up to anything higher than 270 MHz! The clock speed is the same, it's like a threshold which none of the tested video cards was able to get over. This suggests that SiS may have intentionally imposed a limit to the memory controller clock speed, but we won't assert what is not yet known for sure.
At first, the core ran at 300 MHz but after a while the board hanged because of overheating, so we pushed the clock speed down to 290 MHz. Xabre400 withstood that threshold for 30 minutes, but then again failed. Of course it's inadequate cooling that caused the failure, so the maximum stable clock speed we achieved was285 MHz. As a result, the board was overclocked to as high as 285/270 MHz, the average in our test.
Page 6 - Vinix VX-3340 
 |
Top Stories: |
 |
 |
|
MoBo:
| |
|
|
VGA Card:
|
|
|
|
CPU & Memory:
|
|
