today most manufacturers fix there onboard components to the PCI slots to share the IRQ with that PCI slot.
Well sharing is no problem for most components, but for there are still problems here.
I have ABIT KT7a Mainboard, where the onboard is share with PCI4 and I can safly use that slot for my SBLive.
PCI2 and 3 get Network adapters and have both no sharing
and PCI1 is share with AGP and SCSI and Grafik have no shareing problems too.
No I want to buy a new mainboard and don't know wich I could use. I tried ASROCK K7VT2 but it was useless to me four USB controllers all on a different PCI slot, so all have shareing. And the onboard lan had no OS/2 driver :-(
Are there any sugestions? Why does the Tom's Hardware comparison not include such information about wich PCI slot and components have to share? (mostly it's easy to figure that out, mine even shows this in it'S bios-setup).
I am happy about every mainboard inforamtion concerning shared slots.
<P ID="edit"><FONT SIZE=-1><EM>Edited by Birdy27 on 02/20/03 05:52 AM.</EM></FONT></P>
More about :mainboard minimal shared irq pci slots
Just get a board with the minium stuff that you need. You can easily just turn off the stuff you don't need like USB/serial/RAID or whatever.
Tom's hardware probabaly doesn't include such information in its reviews because it is largely irrelevant. Most modern products support IRQ sharing without any problems, for example I have 3 devices sharing IRQ17. Btw what items do you have that don't support IRQ sharing? Your network cards? Because there are always some slots with unique IRQs just like you have now.
First, the hardware is uniquely identified at an electronics level so that only one device comes live at at time. Were it otherwise you'd get some total strangeness like dancing patterns on your monitor when your speakers make sound or wild noises from your speakers when the network is going, etc.
Second, most modern software (especially Win2k and XP) doesn't actually use IRQs for device access. Instead a software contrivance called a "miniport" is used. Miniports uniquely identify each component/board by a Buss and Device ID number, rather than an IRQ. Feed the Buss and Device ID to a register on the southbridge and the device you want pops up. Even devices apparently on the same IRQ are still uniquely identified by this method. In fact, Win2k and XP actually put all devices on the same IRQ, letting the miniports sort it out. The IRQs you see in device manager are "virtual" devices, provided only for compatibility with older software.
Finally, there is next to no performance hit for doing this. Since even though you can trace an on-board device's PC board foil right to a PCI socket, the device is still uniquely identified by hardware and thus can be accessed by software at full speed. There is no turning one device off to get at the other.
Win9x is pretty much outmoded software these days. Board design has moved beyond the old ISA model into something permitting far more I/O than was possible with 16 IRQs. Win2k and Winxp have kept pace with these changes.