Interesting. I wonder if the bottleneck is one of the Wine (Windows 'emulation') libraries. Assuming that you compile the Windows version under Linux against the Wine libraries bible_pay?
I have also noticed that the wallet uses no pagefile resources at all, so a bottleneck could be possible.
Unless you don't have much memory in your computer I wouldn't expect the wallet to need to use virtual memory (the pagefile on the disk), which is a good things as using memory in the pagefile really slows things down. The resource intensive aspect of the wallet is processor usage for mining.
Yeah, I just checked my other miner. Doesn't use pagefile either, but it uses all threads at same hashes per second. Could be the algo used to filter out GPU and AISIC. I have 3mb L3 cache and 4gb ram and it is running at less than 50%. My processor runs at 46-50 degrees, so cant be overheating either.