Shawn Heisey [s...@elyograg.org] wrote: [...]
> If you have a total index size for this JVM of 240GB, then you may not > have enough RAM to let the OS disk cache work efficiently. For that > size of index, I would plan on a system with at least 128GB of RAM, > 256GB would be better. [...] > One of your earlier messages indicated that you are using SSD storage. > Main system memory is quite a lot faster than an SSD, so the OS cache is > still important. While technically true, our internal tests showed little practical gain by using main memory over SSD. Our main search servers are equipped with paltry memory (16GB) and consumer grade SSDs for our 10M documents/70GB indexes. However, we did our comparison testing way back before MMapDirectory with Lucene 2.something, so our observations might not be valid anymore. Do you know of any recent experiments with RAM vs. SSD? Regards, Toke Eskildsen, State and University Library, Denmark
