Paul has much longer experience than I, personally just starting to attack CEP a few weeks ago, but let me add my own experiences.

I have 2 32-thread systems, one with 64GB and one with 32GB, each running the BOINC data directory off an SSD. The 64GB system can run 32 WU simultaneously (though I only run 30 to leave spare CPU for monitoring) and the 32GB system can run 24 WU. This is by my own rule of thumb that each CEP2 WU takes up to 1.2GB of memory between the process' usage and the filesystem cache.

The older 120GB Sandisk SSD is losing 1% of its life (according to SMART data) every 2-3 days; the newer 240GB is losing 1% of its life each week, when used on the 30-WU system. That's the biggest downside I see to SSD usage. I do need to check out the X25 SSDs that Paul mentioned to see if they have better write lifetime capacity.

I tried using a ramdisk on the 64GB system, but that would not allow me to run as many WU; since the Windows ramdisks aren't integrated with the OS, they are stupidly duplicating the same files that are already in the filesystem cache. Since Linux has a built-in ramdisk of sorts, my hope is that there would be less duplication of files in memory, so I could run 30 WU from the ramdisk with occasional backups to SSD/HDD, perhaps improving performance and definitely improving SSD lifetime.

The biggest downsides I see to ramdisk are the data loss on power failures and the extra memory cost (and UPS cost if you want to add some security). However, even with the SSD and a UPS, an extended power failure will still likely cost you more than half of your work in progress since the first checkpoint typically takes much longer than the remaining checkpoints combined.

The X25-E's are older Intel SLC drives with a larger lithography. You can still find them on E-Bay cheaply. They are rated at 2 Petabytes for write endurance, and I over-provisioned the drive through the raid controller by 50% for additional endurance. The MWI after 2+ years is still 95%.

I do also have some 4 core systems on consumer grade Crucial 120 Gb SSDs with CEP and I'm not seeing any significant degradation. I would check to make sure TRIM is enabled since this will have large impact if its not. ACHI also needs to be enabled in the BIOS for TRIM to function. I could personally live with 1% a week although you would have to replace the drive every couple years. The prices have dropped a lot, and a Crucial 240Gb can be had for $60. However 1% every few days is not good.

No work units available for the past 2 or 3 days, is everything ok?

In the last 5 hours or so I've been getting a good work flow of new WUs again across Win, Mac, and Linux machines.

3/26/2016 8:47:36 AM | World Community Grid | No tasks are available for The Clean Energy Project - Phase 2

Been getting this all day, besides HST1 not having any WUs available, as well.