OK, thanks. I am getting more and more convinced that it is essential to do this under Linux in order to get acceptable performance. Until recently, I had no experience with Linux whatsoever, though. So I am learning now how to do elementary things, like editing and compiling. This is why I had a slight pause in the development of my 7-men builder. I have a Linux now running on my native laptop. Before, I tried running Linux under Windows in VirtualBox, but performance-wise this turned out to be a very bad idea; I could not nearly get the disk I/O speeds I am seeing now I really installed Linux in a separate partition. (Fortunately I could easily do that, as I had replaced a crashed 40GB HD by a 120GB one, as it was the smallest one I could buy, but the recovery software only worked if I fooled it into thinking the disk was 40GB as well. So I had still 80GB left to make Linux partitions!
I will install Linux on my 'big' machine as well. (OK, it is a by now pathetic E6600 (2.4GHz Core 2 Duo) with only 1GB DDR2 DRAM.) I do have 2 physical hard drives on that, although they are also not as big as I thought: only 500GB in total, rather than each... But it will probably be smart to write the 7-men generator in such a way that it distributes the tablebase over two files (which in practice will be the raw partitions in /dev/hda* or /dev/sda*, dedicated to EGTB generation), so that it can double the bandwidth.
I am not sure the machine I have now will be up to the task. To run my 7-men algorithm I would at least need to equip it with another 1GB of RAM, and my disks probably would fill up before the building of a generally won EGTB is finished. Although 350GB, distributed over 2 disks, might be enough for end-games that do not require too many cycles. (My primary disk is currently partitioned as a 58.5GB Windows partition, and a 174GB unused partition, while the secondary disk is a single 232GB partition, completely unused. So I could take 58.5GB away from the latter, to install Linux plus a swap partition, and then I would have 2 x 174GB for building the tablebase.) I don't want to invest too much in this old machine; I am looking to buy a new PC based on the Core i7, but I want to wait until Intel releases the 8-core version of that. Although multiple cores is quite useless for tablebase generation, my Chess engine (which I plan to convert to SMP) will need as many cores as it can get...