Quote
Originally Posted by
MisterShan

View Post

Those are regular hard drives? I am so confused as to how you lot even get to those speeds. Like I said it’s way beyond my SSDs continued straight to my system. The drive I am using is actually a TB 2 with a TB 2 to 3 Apple dongle I apply for my Mac Volume Pro. However even TB 2 should be getting much higher speeds no? Basically shouldn’t I exist getting 40gbs? I am confused how this all works.

Hullo Mr. Shan, I came upon this thread in a search since I am having no luck finding any updates for my ASUS Thunderbolt EX3 PICe3 Carte du jour. There take been 3 updates, including the most contempo dated Jan 2019 and ASUS for whatsoever stupid reason still has the 1 from 2017: (17.2.71.250). Anyway, I’m posting to try and demystify where the high speeds are coming from. I’m hoping I will exist able to add an attachment, but just in case, I’ll write out the explanation.

I am using the same Broadcom/LSI MegaRAID 9361 8i controller, which is Gen 3 and will run up to viii Internal SATA6G or SAS12G. The SAS are the SFF SSDs 2.5″ 0.7, and have the same header as SATA6, except EACH ONE runs at 12 Gb/due south as opposed to half dozen Gb/due south. Likewise Mini SAS SSD’s run the gamut with respect to each drive’south speeds. For example: right now I am all the same using eight ten 240GB Toshiba SSD’s SATA6 Gb/due south, waiting for an order I placed for viii x 400GB SAS Micron SSDs. The Max speed of a single SATA6 SSD is well-nigh 550 MB/s Read and about 520-530 Write. Thus, 8 configured as RAID-0, just at the max scaling (no PCIe2 bottlenecks) 550 10 viii = 4,400, or iv.4 GB/s Read and 530 x viii = 4.24 GB/s correct

For some reason I tin’t seem to drag an image of a benchmark on the SATA6 array I am running, but I’ll endeavour when I make the postal service. What you’d encounter is with a Stripe of 128, and with two of my settings being “read ahead” and “E’er write dorsum,” gives me virtually 6 GB/s Read and about 6.viii GB/s Write. The reasons for the speeds higher than just the full scale of the speeds of the 8 drives, is the RAID Controller and also the reason the write speed is faster, is due to something called CacheVault. The 9361 8i for example, has ii one.2 GHz PowerPC processor cores and a 72-bit DDR3 interface
that drives 2 GB cache retentiveness (or 1 ).

I accept been in the IT Business almost 26 years. Dorsum with IDE and very slow drives, even SAS 10K and 15K drives were slow, the answer was always smaller and cheaper drives deployed at RAID-0. I know well-nigh people who are not familiar with RAID believe RAID-0 is dangerous, since they say (correctly) if you lose one drive out of 8 unlike say, RAID-five or 6, there is no (what is called) Parity Drive waiting with a Hot Spare to restore the array which takes dreadfully long. These days in that location are Applications for $50 that can create PITs (Point in Time Snapshots, and also create differential bootable backups to a
single drive
for the latter and to a NAS, or just a Large HDD for peradventure 3 PIT snaps. The key is that if you lot practice lose a drive in a RAID -0 array, $l software does much more than than restore. The same matter EMC NetWorker does. OK, YES, it’south slower but for a personal user with a ii-4TB Bulldoze 1/2 full, a dead assortment, is upward and running inside thirty minutes with one

big

deviation from traditional file backup.

I just realized, that common misconception I hear near RAID-0 may not exist hither. These ROG forums are my 1st go-to many times, I need to brand time to contribute. Anyway…with image or PIT snaps:

At that place is no need to reinstall Os, Apps and files. In fact, if you do not have the time to restore, the automated “bootable” differential fill-in tin be used to boot up and yous can go along what y’all were doing. (Merely, for people who want that power I suggest two bootable backups, so even if your main C:\ drive is made up of viii 10 400Gb drives, iii.2GB total, 2 x 4TB HDD is not that bad to know you lot
always
have a backup and a bootup. The only shock is if y’all practise demand to use the boot drive, be prepared to go back to 60 second and not 6 2d boot ups (Not including the RAID BIOS), until you are set to restore.

How easy is it really? Let’southward say you setup an 8 drive SSD assortment and one drive goes and you lot didn’t pick up an extra one. So what, make the new Array with seven drives, restore information technology and then when you get the 8th yous place it into the backplane, bring up the RAID BIOS and select “import foreign configuration,” reboot and past the time you have restarted, the data on the 7 drives, is properly proportioned using the import procedure to the new 8th drive.

Lastly, these Micron SAS SSDs I have on society, each 1 is 400GB and the speed of each is ane,700 MB/s Read and one,200 MB/s Write. Simply at calibration x eight drives

is 13.6 GB/s Read and ix.half dozen GB/due south write, and so with the controller my guess is I’ll go nearly fifteen GB/south Read and maybe hit 13 GB/southward write. This was just to provide an example of where the speeds are coming from, I’yard not insane needing storage speeds that fast. The Partner nosotros do about of our sales for is VMware. Since I own the visitor I tin can stay home if I’d similar to and still deploy VDIs and even DRaaS, as fast as clients demand them at times. Lots of fast storage and lots of Memory is needed for that. So, with the price of SATA6 SSDs, the depression cost of a controller and because some companies at present make what I’d call a 1U backplane, with a $150 viii drive SATS and SAS Backplane that gets rid of SATA cables, and uses what are chosen 8643 to 8643 SAS cables, two of them, 1 for every 4 drives, no different than any enterprise rack, in the long run, while they take a flake more work, they are the best and least expensive,

We tested a new Intel Optane 905P (an Yard.2 2280 stuck in a expert looking PCIe 10 4 case) and using Crystal I got no meliorate than two.7GB/s Read and two.4 GB/s write, for 1GB, and I believe it lists at least $1,100. But major difference I noticed is latency. It was nigh 25-30% as fast as my current assortment. For 960GB it’southward also more than a dollar a GB, which us what SSDs were 8 years agone. I hope I helped with the speed question.

Thank you

Dean


Click image for larger version. 

Name:	X99-E WS_6G_SSDS_B4_MICRON_MINI_SFF_SAS_12GB_SSDS.JPG 
Views:	2 
Size:	152.6 KB 
ID:	80131