You should be able to use a 64-bit PCI-X card in a 32-bit PCI slot. I've done it before and I even have that EXACT same card you're talking about although used in a 'proper slot' which is PCI-X 64-bit and running at 133MHz.
The only limitation you should encounter is that the 32-bit PCI slot will limit its motherboard connector throughput to 32-bit 33MHz or 32-bit 66MHz (that latter higher frequency may be configurable via your system's BIOS. The connector throughput will limit the card to motherboard throughput to either 133MB/s or 266MB/s, respectively.
The PCI-X 64-bit at 133MHz connection enables card to motherboard communication throughput of 1,067 MB/s.
Correct me if I'm wrong here (others). I do not believe that there are any adapters or converters to get its native top speed via a standard PCI slot. Sorry.
Thanks a lot for reply. I really appreciate your prompt response but optimum speed and performance is not an issue here. This card (Intel PRO/1000 MT Quad-Port Server Adapter is not even fitting into any slot on (asus rampage ii gene) motherboard. This motherboard has pci and pci-e slots. The physical shape of this adapter is, that its 32-bit key is locked, it only fits in longer 64-bit slot. At this time I cannot afford to buy new motherboard after all this PC has Intel i7-940 with 12Gs. Any alternate solution gentlemen? I want this particular adapter to work in my PC.
Check the Wikipedia illustrations of keying for the slots. My guess is that your PCI slot is a 5 volt slot. The adapter requires a 3.3 volt slot, which was found on server motherboards. If you had a either a 32-bit or 64-bit slot with 3.3v signaling the adapter would fit. Because of the difference in keying and signaling, you cannot use that adapter on your motherboard.
Sorry Shawn. I thought it would have worked but, yes I do vaguely recall that older PCI slots were keyed sometimes. I thought this 'keying and voltage' limitation were done away with long ago (i.e. the motherboard could handle and adjust to any PCI type card nowadays).
I'm surprised that the card will not work in such a newer system (i.e. motherboard).
The system I use my same Intel quad-port card in is a SuperMicro X6DAE-G2 (a workstation/server graded board - something Mark H alluded to).
Again, a huge bummer BUT I've looked for these quad-port PCI-X cards on EBay and they STILL sell for primo dollars. You may be able to sell it and then buy an Intel PCIe quadport card. Not kidding. The older PCI-X cards still run in the hundreds of bucks. Both the dual and quad port models (which I have both).