X-bit labs

Shuttle SB81P Small Form-Factor System Review (page 9)

Category: Mobile

by Platon Scheblykin

[ 07/12/2005 | 10:20 AM ]

BIOS and Overclocking

There seems to be nothing extraordinary about the BIOS of the XPC SB81P: the popular Phoenix Award BIOS v6.00PG microcode with typical menu items and navigation. Yet I think this is a real masterpiece. I don’t mean the settings which are sufficient but not outstanding in this BIOS. I mean the design of the menus. First, the main menu contains only the settings that are directly relevant to it. There’s no extra or missing thing here. Second, the settings on each menu page are either combined into submenus or separated with headings which tell you about the nature of the settings that follow. It means you don’t have to seek for a necessary setting in the whole list after selecting a submenu with many items (like Frequency/Voltage Control). And third, many items in the menus come with a detailed tip on what they mean. To cut it short, I simply enjoyed dealing with such a BIOS!

I said above that the BIOS offers a sufficient number of options. I meant all options, but overclocking-related ones are the most interesting, of course. Here’s the full list of them I could find in the SB81P’s BIOS:

• CPU multiplier adjustment from 8 to 50. This multiplier is locked in modern processors, so this setting may not be of a big practical value. Anyway, it’s nice to have it, just in case.
  
  
  
• FSB frequency adjustment from 100 to 355MHz stepping 1 megahertz.
• The memory can work either as DDR400 or as DDR333.
• CAS Latency can be set to 2, 2.5 or 3.
• The tRCD timing (RAS to CAS Delay) can be adjusted from 2 to 5 stepping 1.
• The tRD timing can be varied from 2 to 5 stepping 1.
• The tRAS timing can be changed from 4 to 15 stepping 1.
• CPU voltage adjustment from 0.8250 to 1.5875V stepping 0.0025V.
• DRAM voltage adjustment from 2.7 to 2.9V stepping 0.1V.
• The chipset voltage can be set from 1.60 to 1.80V stepping 0.1V.
• The PCI Express and PCI buses can be clocked synchronously or asynchronously with the FSB. It means you can fix the frequency of these buses down at some definite point.

The last setting is rather tricky. It was present in the menu of the BIOS we received the SB81P with. But after I reflashed it with a version downloaded from the Shuttle website, it disappeared. These two BIOS’s also differ from one another in the following way. The first BIOS allows choosing the general ratios of the graphics memory areas for the integrated graphics core. In the second version you could change the size of each memory area independently.