Using RAM instead of disk for build servers

[Ryan Schmidt]

On Mar 15, 2021, at 16:26, Daniel J. Luke wrote:

> On Mar 14, 2021, at 6:38 PM, Ryan Schmidt wrote:
>> As far as longevity, the previous set of 3 500 GB SSDs I bought for these servers in 2016 lasted 4-5 years. They were rated for 150 TBW (terabytes written) and actually endured around 450 TBW by the time they failed, or 3 times as long as they were expected to last. The new SSDs are rated for 300 TBW, and if they also last 3 times longer than that, then they might last 8-10 years, by which time we might have completely abandoned Intel-based Macs and be totally switched over to Apple Silicon hardware and will have no use for the Xserves anymore.
> 
> Thanks for including this information - it's similar to experience I've had with SSDs for $work. I'd be really surprised if we care about builds on the xserves in 8-10 years (given our previous experience with the ppc to x86 transition).
> 
> I haven't looked recently, but I recall xserves being somewhat picky about their internal drives - have you found that specific SSDs work well (vs others that don't)? I'm assuming you've installed them on the internal trays - but maybe that's a bad assumption.

I heard the same about Xserves accepting only specific internal hard drives, which is why, in addition to being limited to SATA speed, I didn't put SSDs in the drive bays. Instead, I got Lycom DT-120 PCIe adapters and put an m.2 SSD in those. Currently they're populated with ADATA XPG SX8200 Pro m.2 NVMe SSDs. The previous SSDs that failed in the buildworkers were Samsung sm951 m.2 AHCI SSDs. The one that failed in the buildmaster was the Apple original Xserve SSD in the dedicated Xserve SSD bay.