On 01/15/2014 08:50 AM, Sebastien Han wrote:
However you have to get > 480GB which ridiculously large for a journal. I believe they are pretty expensive too.
Looks like the M500 in 480GB capacity is around $300 on amazon right now
VS about $300 for a 200GB DC S3700. The M500 has more capacity (and
thus more cells to spread journal writes over!), but the DC S3700
theoretically has higher write endurance per cell.
In the end, it seems like both have the potential to be good journal
options on paper anyway.
––––
Sébastien Han
Cloud Engineer
"Always give 100%. Unless you're giving blood.”
Phone: +33 (0)1 49 70 99 72
Mail: sebastien.han@xxxxxxxxxxxx
Address : 10, rue de la Victoire - 75009 Paris
Web : www.enovance.com - Twitter : @enovance
On 15 Jan 2014, at 15:49, Sebastien Han <sebastien.han@xxxxxxxxxxxx> wrote:
Sorry I was only looking at the 4K aligned results.
––––
Sébastien Han
Cloud Engineer
"Always give 100%. Unless you're giving blood.”
Phone: +33 (0)1 49 70 99 72
Mail: sebastien.han@xxxxxxxxxxxx
Address : 10, rue de la Victoire - 75009 Paris
Web : www.enovance.com - Twitter : @enovance
On 15 Jan 2014, at 15:46, Stefan Priebe <s.priebe@xxxxxxxxxxxx> wrote:
Am 15.01.2014 15:44, schrieb Mark Nelson:
On 01/15/2014 08:39 AM, Stefan Priebe wrote:
Am 15.01.2014 15:34, schrieb Sebastien Han:
Hum the Crucial m500 is pretty slow. The biggest one doesn’t even
reach 300MB/s.
Intel DC S3700 100G showed around 200MB/sec for us.
where did you get this values from? I've some 960GB and they all have >
450Mb/s write speed. Also in tests like here you see > 450MB/s
http://www.tomshardware.com/reviews/crucial-m500-1tb-ssd,3551-5.html
Looks like at least according to Anand's chart, you'll get full write
speed once you buy the 480GB model, but not for the 120 or 240GB models:
http://www.anandtech.com/show/6884/crucial-micron-m500-review-960gb-480gb-240gb-120gb
that's correct but the sentence was " The biggest one doesn’t even
reach 300MB/s."
Actually, I don’t know the price difference between the crucial and
the intel but the intel looks more suitable for me. Especially after
Mark’s comment.
––––
Sébastien Han
Cloud Engineer
"Always give 100%. Unless you're giving blood.”
Phone: +33 (0)1 49 70 99 72
Mail: sebastien.han@xxxxxxxxxxxx
Address : 10, rue de la Victoire - 75009 Paris
Web : www.enovance.com - Twitter : @enovance
On 15 Jan 2014, at 15:28, Mark Nelson <mark.nelson@xxxxxxxxxxx> wrote:
On 01/15/2014 08:03 AM, Robert van Leeuwen wrote:
Power-Loss Protection: In the rare event that power fails while the
drive is operating, power-loss protection helps ensure that data
isn’t
corrupted.
Seems that not all power protected SSDs are created equal:
http://lkcl.net/reports/ssd_analysis.html
The m500 is not tested but the m4 is.
Up to now it seems that only Intel seems to have done his homework.
In general they *seem* to be the most reliable SSD provider.
Even at that, there has been some concern on the list (and lkml) that
certain older Intel drives without super-capacitors are ignoring
ATA_CMD_FLUSH, making them very fast (which I like!) but potentially
dangerous (boo!). The 520 in particular is a drive I've used for a
lot of Ceph performance testing but I'm afraid that if it's not
properly handling CMD FLUSH requests, it may not be indicative of the
performance folks would see on other drives that do.
On the third hand, if drives with supercaps like the Intel DC S3700
can safely ignore CMD_FLUSH and maintain high performance (even when
there are a lot of O_DSYNC calls, ala the journal), that potentially
makes them even more attractive (and that drive already has
relatively high sequential write performance and high write endurance).
Cheers,
Robert van Leeuwen
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
