| From: Russell Reiter via talk <talk@gtalug.org>
| Optane was intended to be a cache memory to increase the performance of
| conventional spinning HD's under Windows OS. However, I've been booting
| Fedora from both a 500gb SSD and 32gb Optane Nvme as I tinker with my own
| desktop.
I think Optane is just a brand name and that brand name gets attached
to several different things, some of which are not yet being sold.
True enough, sometimes it's hard to sort specifications from hyperbole.
The original promise was: non-volatile memory that would get speed
close to RAM and price close to flash. (They also need better
durability than flash.) There's a big gap between those, and anything
in between ought to have a market. They just haven't been able to
accomplish much.
- they wanted to produce things that fit in RAM sockets. That meant
either
(1) no change from RAM interface (unlikely, but suggested-by-omission
in early marketing) or
(2) memory interfaces that were augmented to support the new protocols
(delivered with some new Xeons, I think)
- the NVMe stuff has had much worse durability than originally
promised.
- the NVMe stuff has had quite small capacity compared with most SSDs
- NVMe SSD has mostly been fast enough that the Optane stuff isn't
compellingly better
| Most certainly booting to a login prompt is fractionally quicker
| on the Nvme than on the conventional SSD.
That's what I'd expect. But I'll admit to no experience with Optane
and I haven't been following it closely.
| However recently I up-sized my
| Nvme and have populated my M.2 slots with a 250gb WD black Nvme for boot
| and now added an additional 1TB to the second M.2 slot with F29 still on
| the SSD. Copying a 100gb image to the 1TB drive really hit performance tho
SSDs come with different performance trade-offs. Most inexpensive
SSDs have (on-board) controllers with only small amounts of RAM. This
makes them slow down a lot after a modest burst of intensive writing.
That's a fine trade-off for many of us but not for all workloads.
You can pay more and get SSDs with enough RAM to not have this
performance problem. I don't know enough to give specific advice.
I have recently learned that some cheap NVMe drives can ask the OS to
allocate system RAM for the exclusive use of the controller. This
isn't a conventional data cache, but something much stranger. It's
called "Host Memory Buffer" (HMB). I think that vendors don't explain
it because they think consumers won't understand it.
HMB might be a great trade-off, or a horrible hack. I don't know.
What happens when the power fails? Or when the system crashes /
reboots?
Recent Linux and Windows support HMB. I assume that UEFI firmware does
not. So use of HMB must be an optional speed-up.
| and that was probably due to the lack of a decent heat sink.
| I just ordered a hteatsink fro the internal 1TB
Why do you think that this was heat-related? It might be, but that
would not be my first guess. (I am not an expert on this.)
Apparently, at least on Crucial products, there is built in thermal monitoring which will throttle speeds.
Here's a link to the 1TB Nvme. On sale for the next few days for $147.00, about $40.00 less than I paid.
Here's a link to a review of Crucial's Thermal Throttling capacities
| Perhaps with the NUC form factor heat might
| be a problem on a larger sized Nvme but with USB-C you have wiggle room for
| adaptation.
The NUC form factor certainly reduces the heat disposal and thus
limits components. But the main such component is the CPU. I've not
heard of it being a problem for consumer 3.5" SSDs (what Evan intends
to use) or NVMe drives.
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