Subject: Re: A simple way to transfer photos from your phone to Windows withoutinstalling anything on either
> In article<email@example.com>, Ken Blake
>>> I've bought a new terabyte disk, and now have two terabyte disks side by
>>> side (which I might RAID once I clean them out - but I never did RAID
>>> before and googling finds that there are a LOT of up-front decisions to
>> If you mean RAID 0 (striping), although it sounds like it should speed
>> up disk access, my experience is that it doesn't.
> then you did something wrong, perhaps using a shitty raid controller or
> it was bottlenecked with a slow link, such as usb 2.
> raid 0 definitely speeds things up, but doubles the risk of failure.
With an Areca card and multiple HDD disks in Raid0, you can hit
2GB/sec sustained. The limitation on cards like that, was the onboard
processor. The clock rate on the processor was rising with time.
(At one time, the RAID0 was only 800MB/sec or so.)
The cards handle RAID5 (which needs XOR) as well as RAID0
(which doesn't need XOR), and the processor on the card probably
isn't adding a lot of value when running RAID0. But Areca
is pretty happy to have you buy the card anyway, and
the card supports RAID0 for the "racing crowd". The largest
card might have had 24 SATA connectors on it.
Even a single NVMe Flash storage product today can hit I/O
rates like that, and with a much cheaper infrastructure cost.
The Areca cards, the really big ones, were $1000 each.
Whereas regular people can afford to buy NVMe products
(suitable for scratch disks say). The NVMe wouldn't be a
particularly good format for archival storage (your
finished product), but might be good to make your movie
editor go fast.
I still haven't figured out what technical endeavor NVMe
was invented for, and the speed isn't always well matched
by the rest of the computer. (Lots of stuff
you do, won't be saturating your NVMe. For example, the
CRC32 hash program I use as a speed benchmark, only hits
1.3-1.5GB/sec, when an NVMe can do 2.5GB/sec. And I can't
think of too many other programs that work that fast.
Many other programs are happy to putter along at 300MB/sec.
If you're not a very good programmer, you should be able
to hit 300MB/sec. Hitting the higher rates takes work.)