Is this S914 config a good replacement for my S814 Re: (was: What is the difference between Flash storage and a Flash Storage system like the V9000/V7000)

Gad,

Good idea to change the Subject if you want to catch the eye of those who can help!

Jim already made several good points but overall I would amplify his suggestion that we don't know enough. You might have only 7 drives that provide that 6TB of space. If you do they are 1.1TB and 10K RPM so the proposed SSD configuration would look like a Top Fuel dragster against my Prius. Or you might have multiple drawers of 139GB 15K RPM drives on several large cache controllers in a mirrored environment. MASSIVE difference between those two options!

In either case it's likely the new SSDs will win big but we're guessing.

One more thing, Where are you getting the 'SSD writes are only slightly faster than HDD writes' statement? Waaaaay back the original 70GB SSDs that IBM sold for a kings ransom had write speeds of about 120MB/s which is rather comparable to a 15K spinning drive on streaming writes. But the SSD generations released in 2016 were well over 400MB/s (as high as 470MB/s)

And in IBM's latest SSD announcement they state: Write performance is "more than 25 times that of a standard 15K HDD" and "the number of drives is still a factor in achieving satisfactory performance, especially for IBM i."

Read all about em here: https://www-01.ibm.com/common/ssi/cgi-bin/ssialias?infotype=an&subtype=ca&appname=gpateam&supplier=897&letternum=ENUS117-086

So I think you have some outdated information there. Even PC SSDs today are pretty close to parity for read and write performance with writes only a tick slower than reads any more.

- Larry "DrFranken" Bolhuis

www.Frankeni.com
www.iDevCloud.com - Personal Development IBM i timeshare service.
www.iInTheCloud.com - Commercial IBM i Cloud Hosting.

On 3/31/2018 6:45 AM, Gad Miron wrote:

Calling all sages

We're going to replace our S814 (3 cores activated) 6 TB internal HDDs
machine
with a S914 (3 cores activated) 18 931GB Mainstream SAS 4k SFF-3 SSD
machine.

Is this a viable DASD configuration for a write intensive environment?
(it is common knowledge that SSD writes are only slightly faster then HDD
writes right?)

TIA
Gad





date: Wed, 28 Mar 2018 13:29:31 +0000
from: Diego Kesselman <diegokesselman@xxxxxxxxx>
subject: Re: What is the difference between Flash storage and a Flash
Storage system like the V9000/V7000

IBM Power Systems HDD and SSD options offer enhanced performance at a lower
cost and deliver server enhancements

https://www-01.ibm.com/common/ssi/cgi-bin/ssialias?infotype=
an&subtype=ca&appname=gpateam&supplier=897&letternum=ENUS117-086

BTW: V9000 is as fast as internal SSDs, but I've seen high workloads on
enterprise systems wih no performane impact and no changes on service time
(always 0.3x ms, even on backup window)

I'll discard V5x unless you need storage on a budget. You'll feel
degradation from your enterprise SSDs

El 28 mar. 2018 07:18, "Steinmetz, Paul" <PSteinmetz@xxxxxxxxxx> escribi?:

Diego,

I'm currently using internal Enterprise SSD - 775gb SFF-2 SSD for IBM I
ESOH.
I've talked to some performance folks, and most agreed you can't beat
internal SSD with a top controller.


< On the other side there's a "mainstream" 931GB SSD with same price per GB
as an HHD, and 18% faster than a normal SSD.
What do mean by this?


Paul