I also like to share my experience with FB 2.5 on Win 64. I took a different path to optimazed FB performance.
From the very beginning I have choosed SC architecture for its multiple thread capability. And these are the main setting in my db - Page Buffers = 1024 - DefaultDbCachePages = 0 I set these parameters to its min value because Firebird database is placed on a RAM disk. I predict my database size won't exceed 64GB and also I can upgrade CPU RAM up to 128GB. With those setting, you have SC architecture with share cached like in SS. CPU has a UPS and backup runs 3x times a days. It has been runs about 3 years without serious problems. I don't know how its speed compared to database on a disk, but it is very fast. Just for raw info, on SSD(sata 2), random read 4K +/- 18 MB/s, random write 4K +/- 52 MB/s. On RAM, random read 4K +/- 1061 MB/s, random write 4K +/- 770 MB/s.
