DaveZ1
2 Iron

Re: SATA EFD's ?

"But i still thinks it's strange EMC marked the SATA drives (EFD or spindle) as 3Gb speed, this confuses people"

Full disclosure requires us to indicate the core technology of the drive. Which, as Lars correctly pointed out, is a better performing drive than previous. Anyway, the tecnique of interfacing the 3 Gb SATA devices to the FC back end is well-known, proven and stable -- and we get excellent performance. THese drives give great IOPS and bandwidth. Note our existing SATA II are 3 GB and you can hit the same back-end bandwidth with them as you can with FC drives. The 3 Gb internal speed is not an impediment in a shared bus/loop arrangement.

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Spril1967
2 Bronze

Re: SATA EFD's ?

Thanks David, but what is the factual speed difference between SATA and FC EFD's ?
I was not managed to find technical information on the Samsung SATA EFD's. but i will try to write to Samsung to get the data.

because if the SATA EFD are as good (Performance vise) as FC EFD's, why have FC EFD's ?

I can se that the FC EFD Stec Zeus drives have

READ & WRITE PERFORMANCE

Read:  350MB/s
Write:  300MB/s

IOPS READ & WRITE PERFORMANCE

Read:  Up to 80,000
Write:  Up to 40,000

And whit a SATA protocol limitation of 300MB/s (Theoretically from Wiki) then the SATA EFD's cannot be as good as the FC EFD's

So in my point of view the FC EFD's are still better for use to FAST CACHE, as the DRAM Cache can better use the performance of FC Protocol

Just my 5 cent's 🙂

Kenneth

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DaveZ1
2 Iron

Re: SATA EFD's ?

Kenneth I do not have the time to get into a long debate encompassing the dozen or so factors that affect EFD peformance in the real world. If you would like the 'proof of the pudding' have your local USPEED guy do some estimates with the Disk Sizer tool (USPEED only tool).

It turns out comparing manufacturers metrics is an exercise in futility as there are many internal architectural differences which affect real-world performance under a range of different conditions.

"And whit a SATA protocol limitation of 300MB/s (Theoretically from Wiki) then the SATA EFD's cannot be as good as the FC EFD's"

Sorry, that is only 1 factor and it RARELY applies to how the drives are used. Trust me, I have no reason to misrepresent the truth. I do not get paid for selling one thing over the other, I am motivated by happy customers.

Why have both? It is an expanding universe of choices and EMC is always at the forrefront.

thank you for your interest - please take up specific sizing questions with a USPEED rep, he/she will get the answers you need to the solutions yuo must build.

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DaveZ1
2 Iron

Re: SATA EFD's ?

For some insight on those architectural issues - which I presented at 2010 EMCWorld, Flash Drive Architecture (attached, since they no longer end up on PLink)

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Spril1967
2 Bronze

Re: SATA EFD's ?

Great Thanks David, this presentation is good, but this gives me anohter question

Does Sata EFD's also have 16 data opertions lanes ?

Will talk whit our local presales guy, about that tool thanks.

Kenneth

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DaveZ1
2 Iron

Re: SATA EFD's ?

HI Kenneth - I don't have a detailed archi doc on the Samsung - they are holding their design closely. But of course lane count is not hte only factor, speed of access is as well. Basically, we know they perform as well or better in some cases than the FC models we use.

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Spril1967
2 Bronze

Re: SATA EFD's ?

Hi again David

"we know they perform as well or better in some cases than the FC models we use."

have you somekind of proof on that one, grafs ore arctichels,

That sound silly for me whit the small SATA interface, compared to FC 🙂

Kenneth

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DaveZ1
2 Iron

Re: SATA EFD's ?

As I stated before, please have your TC contact a local USPEED rep to run through the nubmers.

And forget the 3 GB vs 4 GB difference, let me ask you - if a highway has 4 lanes, is it 'slower' to dragrace down than an 8-lane highway? NO it is not. And the way SSD are most used - small random IOPS, it is a drag race, The width of that highway is immaterial. All for now, your meter has run out! 😉

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rkelly1
1 Copper

Re: SATA EFD's ?

Can FC SSD disks hot spare SATA SSD disks.  We just tired a copy to hot spare on the CX4 and it will not let us select disks that dont match the exact type.

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Avi3
3 Zinc

Re: SATA EFD's ?

Only Flash drives can spare for another failing flash drive for performance reasons. So the behaviour that you are seeing is as expected.

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