Generally you want to go for drivers from the chipset manufacturers, regardless of which ODM made the boards and which OEM sold them. If there's SiS 530 in there, you need SiS 530 drivers. Without pics we can't comment on the ID as Acer V75M, but IBM certainly did use many Acer boards.
You'll also need drivers for any onboard devices. The V75M has an ESS sound chip (probably a Solo-1).
What's not onboard is VGA. That is integrated into the SiS 530 chipset - and the distinction between onboard (a separate chip on motherboard with its own RAM) and integrated (no separate chip, no own RAM) is very relevant for your performance question.
Integrated VGA shares system RAM. That costs you a few MB, but far worse: it also costs you half the memory bandwidth to CPU in tasks which are both CPU and video-intensive, i.e. games. The IGP in the SiS 530 is the SiS 6326, which in itself is a poor performer as standalone chip with its own RAM, both in Windows 2D and 3D, and even in DOS. Integrated, you can basically halve all those scores again. That makes it slower than an S3 Virge in 3D, so slower than any nVidia chip (with possible exception oft eh nV1) and slower than any ATi chip newer than the Mach64. VESA compatibility (DOS SVGA) is decent, not as good as S3 or nVidia, but better than ATi. As for Matrox, a Millennium I would perform better in Windows.
Put another way: just adding a PCI SiS 6326 would double performance straight away, anything else would likely improve it further. Native SiS 530 integrated VGA is less 'proper socket 7' and rather the sort of low-end experience performing far worse than CPU numbers would lead to believe. With PCI VGA though the SiS 530 is fine, on par with Via MVP3 or ALi Aladdin V for the most part.
