10 Replies Latest reply on Apr 29, 2016 12:18 PM by mikeklar

    Intel SSD 750 Series

    mikeklar Level 1

      In a weak moment I just bought one Intel SSD 750 Series 800GB HHHL (SSDPEDMW800G4x1), primarily due to a price drop of CDN $100 (i.e. CDN $729).

       

      I've been looking to replace one remaining spinning drive, but find myself questioning this decision as the 750 series write speed is specified at only 800 MB/s, which is a lot slower than my Samsung 950 Pro M.2 (at 1527 MB/s) and the four Samsung 850 Pro in Raid 0 configuration (at 1833 MB/s).

      However, I can live with the read speed of the 750 which is specified at 2000 MB/s.

       

      The idea is to use the SSD 750 in place of the existing System SSD drive and use the latter for various none video and image related data, which is presently on a HDD.

       

      My quandry, should I return the Intel SSD 750 (have'nt opened the package yet) and wait for a faster PCIe version price drop, or am I being too critical...

      Anyone here using this drive and what are your thoughts?

        • 1. Re: Intel SSD 750 Series
          ECBowen Most Valuable Participant

          Yes I would return the 750 and use the 950 Pro as the OS.

           

          Eric

          ADK

          • 2. Re: Intel SSD 750 Series
            mikeklar Level 1

            Yup, you're right and return it I will.

             

            Now, since I'm still bent on the idea of getting rid of the spinning drive and replacing it with faster SSDs, and stay with the concept noted above, what do you think about the following:

            • Buy four Samsung 850 Pro 250GB drives and use the remaining four ports of the ARECA 1883ix16, configuring said drives as either RAID 0, or RAID 5 ?  One issue with this being the existing tower doesn't have any more slots available to securely mount these drives, thus requiring some kluging... not a big deal though.
            • Buy another Samsung 950 Pro M.2 and a PCIe 3.0 adapter ?

            Regarding the latter, it doesn't look like there are any PCIe RAID cards to allow for two 950 Pros to be configured as one drive?

            Also, using the ARECA card has an issue, that being the limitation of the size of the on board cache if full will significantly slow the transfer speed down, as well the battery backup module cannot be used if maximum transfer rates are required.  Below is an example of the four drives and as compared to 950 Pro.  You will note size of the sample file is set at 32GB, if it were to be smaller than the 8BG of Cache the read/write speeds would be incorrect.  At least that's what I've been given to understand.  I bring this up only as a concern as to what is the real speed of these configurations...

            Your thoughts are appreciated.

            Cheers

            • 3. Re: Intel SSD 750 Series
              ECBowen Most Valuable Participant

              I would buy 2x of the Samsung 850 Pro 512GB or 1TB drives and put them into raid 0 on the Areca. You could get 3 and put them into raid 5 if you want redundancy as well. I rarely suggest the smaller SSD's for raids since there are differences in endurance rating often between the 256GB drives and smaller and the 512GB drives and over. The price points are so close I would just get less larger SSD's and put them in raid 0.

               

              Eric

              ADK

              • 4. Re: Intel SSD 750 Series
                mikeklar Level 1

                Me thinks you've convinced me.  Just one more question:

                Using the ARECA card's ports and having four (rather than two) drives in RAID 0 configuration give me the speed read/write speeds I'm looking for.  The only caveat being the ARECA's cache limitation...

                Am I missing something?

                Cheers

                • 5. Re: Intel SSD 750 Series
                  ECBowen Most Valuable Participant

                  Understand the cache on the controllers almost always gets used up regardless with media because the video files are many and large amounts of data. So most raid controllers will not run cache only sustained speeds which are peak when editing. It would be nice but rarely is it the case. You always plan based on sustained speeds which are closer to the 32GB numbers for example and that is the case regardless of which controller. The Areca cards that offer the option to add cache via ram modules just extend out the cache speeds longer ie more GB at a time before the speed starts to normalize for the controller on the SSD or the mechanical drive.


                  Eric
                  ADK

                  • 6. Re: Intel SSD 750 Series
                    mikeklar Level 1

                    Do I understand you correctly - the disk speed software read/write performance data is incorrect in that once the cache is filled up the performance will slow down?

                    That being the case the real speed performance will deteriorate to the normal speed of the drive once the cache is full.

                    Regardless if this is a multiple disk array, i.e. RAID 0?

                    I really appreciate your input as I'm not seeing the results from the RAID 0 configuration shown earlier in this thread, but keep getting all kinds of data feedback that contradicts my findings.  Also, when the sampling size (Crystal Disk) is below the size of the cache the performance shown is often two to three times higher than what you see in the pasted copies above, i.e. the cache on the RAID card is 8GB and the test size sample is set at 1GB not 32BG?

                    • 7. Re: Intel SSD 750 Series
                      ECBowen Most Valuable Participant

                      What I meant was cache speed ie when the cache is handling all the read and write instructions for drive requests gives significantly higher performance since ram is far faster than disks or sata controllers. This performance is normally called burst rate or peak transfer rates. Once the cache fills though then the performance starts to normalize to what the sata controller can handle ideally. The drive itself also limits this based on the speed and latency the drive can handle those requests in queue. The longer it takes to completely fill the cache the longer the drive or raid maintains the burst transfer rates. Once the cache fills though the transfer rates start to drop. The 8GB cache is standard for most highend SAS controllers and gives you excellent performance for raid's since the raid instructions are stored in cache versus handled realtime out of system ram or from the drive. This allows the controller to handle tasks as fast as it can without waiting on the drives to provide more data or be ready for more data to write.

                       

                      SSD drives will slow down over time from writing and deleting allot of files from them. This is due to how the firmware of the SSD's avoid the permanent erase write cycles. You can return an SSD to original performance by formatting it or writing zeroes to it. When using SSD's for media raids this becomes a standard maintenance process you want to do periodically.

                       

                      Eric

                      ADK

                      • 8. Re: Intel SSD 750 Series
                        mikeklar Level 1

                        Thank you Eric

                        This is as I perceived it, but you put into language that's much clearer.

                         

                        ... Just had an epiphany could it be the number of lanes the RAID card uses limits the r/w speeds when multiple RAID configurations are being used on the same RAID card?

                        My reasoning stems from practical observation, i.e. using the cashing drive (which is the raid 0 drive shown earlier) at the same time the files are worked on from another array in the same card there seems a distinct drop in speed.   I've yet to figure out how to perform a measurable test for that.

                        Cheers, and thanks again for responding.

                        • 9. Re: Intel SSD 750 Series
                          ECBowen Most Valuable Participant

                          The current 12Gbs cards are PCi-E 3.0 8X cards so there is more than enough PCI-E lanes and bandwidth available provided your system has PCI-E 3.0 slots and the card is in a 8x or 16X slot. The Raid controllers themselves have processor chips on them which is why you want the SAS controllers versus onboard controllers or software raids. The current Raid controllers use dual core chips so those chips function the same as CPU processing units in the threading aspect ie the amount of requests that can be handled simultaneously is decided by the number of threads at the raid controller processor. That is likely what you are running into. Caching helps alleviate slow down from multiple raids on 1 card but the controller wont be able to use both cores on 1 raid volume when running more than 1 raid on one controller and using both raids at the same time.

                           

                          Eric

                          ADK

                          • 10. Re: Intel SSD 750 Series
                            mikeklar Level 1

                            I think we are on the same page, glad to see that old brain of mine is still functioning a little

                             

                            So the answer to my dilemma would be to acquire another SAS RAID card and use multiple SSDs to create a raid 0 or 5 configuration that exceeds  two TB, as well gives me the r/w speed I would like.

                             

                            Or, hope someone will come up with a PCIe adapter for multiple M.2 SSDs with a built in raid controller.  That would be the ultimate solution

                             

                            Frankly, I've never been a fan of software raid solutions and been reluctant (most likely wrongly) using on onboard controllers.  Perhaps if I get over my bias the onboard raid controller would be the cheapest and immediate solution.

                            FYI the motherboard is ASUS' X99-E WS USB3.1 and the CPU is i7-5930K.  The latter is scheduled to be upgraded to either eight or ten core when the latter becomes available.

                             

                            Cheers