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My PC case is put under the desk. I have many hard disks for storage and backups. I bought some "cages" which can hold 5 hard disks and mount a fan. And the cages are put on the desk (cable length around 1 meter), for easy swapping hard disks (while PC is off), and less dusty also.

This setup is already running. I am using (0.5 meter + 0.5 meter in serial) two SATA cables to connect from the motherboard to my hard disks on the desk. I know the length limit of SATA cable is 1 meter. This may be the reason why my hard disks sometimes disconnect, as I am pushing beyond its length limit (including the motherboard circuitry).

My ideal setup will be putting hard disks even further away than 1 meter, approaching 2 meters or even a bit more.

I have a few (not yet feasible) ideas:

  1. Any consumer grade SATA Signal Repeater? (I found the Renesas website. But they are not for home use.)
  2. If I convert SATA to eSATA at the motherboard, and convert back from eSATA to SATA at the harddisk, can the length limit go beyond 1 meter, and approaching around 1.8 meter? (eSATA length limit is 2 meter.)
  3. USB cables are much longer. And USB repeater (active USB cable, with power supplied) are very easily available. But converting SATA to USB3.0 seem slowing down the data transfer a lot. (But in the Wikipedia table, USB 3.0 could be as fast as SATA theoretically.)

Edit:

Thanks all the replies. I learnt a lot more.

  • My motherboard is relatively old. There are only USB 3.0 ports, no USB 3.1.

  • I am using cheap hard disks as I am doing RAID1. I just realise that their speeds are just only 230MiB/s.

  • Learnt from this webpage that USB3.0 typical transfer speed is around 300MB/s.

  • I was using SATA cables, not converting to USB connections for two reasons:

    1. It is because I felt USB was quite slow. However, it seems to be my misconception of my USB 2.0 experiences. Even if using USB 3.0 (300MB/s), the bottleneck is obviously the speed of my mechanical hard disks (230MiB/s).
    1. I want as least conversion as possible, and as few intermediate elements (e.g. USB to SATA convertor) as possible, in order to maintain the reliability. However, my currently 0.5m + 0.5m SATA cable connection is failing once a few days. It is already not reliable.

To sum up the points above, it is likely that converting to USB 3.0 seems to be the best solution. It allows me to hot swap the hard disks as well.

My setup would be (from PC) an Active USB3.0 extension cable, followed by a Powered USB 3.0 Hub, and lastly some USB3.0 to SATA3 convertor with power for each 3.5" mechanical hard disks.

Those three elements in the connection are powered (in another words, active) which I hope they would ensure stable connection. However using a USB hub is not a good idea. I will fall into the transfer speed bottleneck pitfall again. All the hard disks connecting to the hub will be limited to a sum of 300MB/s. (i doubt similar bottleneck applies to single USB connected DAS devices also.) Using a hub will get better cable management. OTOH to avoid bottleneck, I should connect each hard disk directly to the motherboard individually. (preferably to different USB controllers on the MDB also.)

Any things I need to be aware of? Among those three active powered electronics, there are many low quality copycats from less reputed companies. How can I choose the best ones?

Deleted as we should not ask how to choose a real world product here. Let us stay in the theoretical realm. Btw I have chosen a seems to be relatively reliable brand of "USB3.0 to SATA3 convertor with power". They had quite a lot of buyers but I do not see many complains of faulty copies.

midnite
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    Why not put them in USB 3.1 enclosures instead? That is what protocols such as USB 3.1 are for. And I explicitly state USB 3.1 because it can have speeds up to 10Gps which is more than speedy enough for most purposes. Read up on the [specs and such here](https://www.digitaltrends.com/computing/what-is-usb-3-1-when-will-it-be-released-and-what-will-it-do-for-pcs/). – Giacomo1968 Oct 07 '20 at 19:56
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    At this scale the right answer would probably be to use a NAS or at least a DAS rather than connect disks directly. – gronostaj Oct 07 '20 at 20:04
  • If a NAS is not in your price range, then certainly you will benefit from a USB drive bay or enclosure, or even just a simple adapter. I personally use an Orico 2-drive docking station for when I need quick access to sata drives. – Sam Forbis Oct 07 '20 at 21:23
  • @Giacomo1968 - Thanks for reply. [My motherboard](https://www.gigabyte.com/Motherboard/GA-B85M-D3H-A-rev-10) is relatively old. There are only USB 3.0 ports. But after [learning all these technologies](https://www.tested.com/tech/pcs/457172-why-storage-drive-speeds-dont-hit-their-theoretical-limits/), and considered the length requirement, and thanks for your webpage link, I think converting to USB 3.0 will be likely my solution. It adds hot swapping feature too, which is sweet. More details are updated above. – midnite Oct 08 '20 at 06:43
  • @gronostaj - Thanks for reply. I didn't heard of the term DAS. But in fact I am already doing a DAS, via SATA cables. I think I will change to USB cables. More details are updated above. – midnite Oct 08 '20 at 06:44
  • @SamForbis - Thanks for reply. In fact I am building this PC to act as a NAS for my other devices. I do not like those pre-built NAS packages, as the number of bays are so limited. Extra bays are ridiculously overpriced. It is indeed just a plastic box, with some cables and a fan. In addition, they will be less secure than my Linux file server. LBNL they are less possible for me to do customisation & programming. I plan to build on ZFS with LUKS. I had a Orico 2-bay RAID1 enclosure too. But it also had the disconnect problem. It seems not so stable to me. More details are updated above. – midnite Oct 08 '20 at 06:50
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    If you're building a NAS, consider a [multi-bay NAS-centric case](https://a.aliexpress.com/_BT2oaJ) or used server-grade disk shelves. You need reliability and loosely hanging cables are not reliable. – gronostaj Oct 08 '20 at 06:58
  • @gronostaj - Good point. Thanks again!! Especially I am planning to keep a cat also. I am still figuring how to solve the hanging cables problems - LOL – midnite Oct 08 '20 at 07:12
  • @gronostaj - But using a NAS case seems not so feasible also. I have to put the NAS case under the desk, which is not so convenient to swap HDDs. More importantly the motherboard seems cannot be mounted inside the case. I have searched for other similar NAS chassis also. Most of them seems quite "raw" and again overpriced (especially with shipping cost added). Yet your point (no dangling cables) is still very good. I think I will consider using the USB approach mentioned in my edit. And get a better "cage" holding my HDDs on desk. There will be only a few USB cables bridging from PC to HDDs. – midnite Oct 08 '20 at 08:50
  • USB is not a great idea, see [What would happen when USB devices draw more power than the hub can provide?](https://superuser.com/q/1538975/194694). – gronostaj Oct 08 '20 at 09:04
  • Also: you're not going to be swapping these disks daily. Unless you'll be running >8 disks, this 1 or 2 occasions a year when a disk fails and you have to dive under the desk shouldn't be that much of a hassle. If you need something that will fit a full-sized motherboard, Fractal Define 7 seems to be quite popular since it can fit 14 (!) 3.5" disks. – gronostaj Oct 08 '20 at 09:09
  • @gronostaj - Thanks again!! In my case, I have dozens of small size HDDs and I do need swapping around, once a few days, or even a few times in a day. Thanks for referring to another question that USB hub is not a good idea. I did forgot about the bottleneck of an USB hub. I should not use that 7-port hub when I need better transfer speed. But the hub I quoted is 48W I guess power is not a problem for it. – midnite Oct 08 '20 at 10:36
  • @gronostaj - Sorry I still cannot see what is the huge benefit to buy a pre-built DAS (other than a better chassis). In most DAS there are only 1 USB cable connecting to the PC. But in my setup I can have every dedicated USB cable from each HDDs to each PC USB port. Of course I need to have some cable management coils in between. The Fractal Define cases are really nice and very flexible!! Even small size "Node" cases can house 6-8 HDDs. I will consider them also. Btw I am using Corsair 280X with mATX motherboard. – midnite Oct 08 '20 at 10:38
  • Let us [continue this discussion in chat](https://chat.stackexchange.com/rooms/113859/discussion-between-gronostaj-and-midnite). – gronostaj Oct 08 '20 at 11:02
  • @midnite Well, the problem now is the title of your question and your quick shift to USB 3.0 has made this question something that this site is not about: Hardware shopping advice. Voting to close. – Giacomo1968 Oct 08 '20 at 17:37
  • @Giacomo1968 - Thanks for follow up. The USB approach is what you suggested. Generally I agree this seems to be the best solution so far. But some others oppose this USB setup for RAID... well, should we close a question because I agree with your suggestion? – midnite Oct 08 '20 at 18:04

2 Answers2

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It depends on you minimum requirements. In layman's terms, if cable length and performance is important and the HD's only goes to one PC I would advice to implement SAN/iSCSI (that's what I use myself in such a scenario). If you need access for more then one PC a NAS would be the way to go and NAS is more common for personal setup then iSCSI. With both ways you can use one or multiple (via link aggregation) wired connections for greater performance then with a single cable.

Other then that you already know the alternative DAS options (USB-hub/USB, eSATA, and Thunderbolt might be an option as well). The problem with USB, SATA, etc. is that you can not scale performance easily, aggregation via Ethernet is much more common and less expensive other then that.

UPDATE: With the additional details in your question, I think DAS is the better option in your scenario (since your requirement for 2m length and USB 3.0 data throughput is quite moderate).

Albin
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  • Thanks for reply. I didn't heard of iSCSI. But as far as I just learnt, iSCSI is a bunch of devices connected via LAN cables (or may be fiber). What I am concerning in my question is, that specific _one_ device within the entire iSCSI setup. Please correct me if I get it wrong. Thanks. – midnite Oct 08 '20 at 06:51
  • @midnite You are semi-wrong, In it's simple form (how I use it mostly) iSCSI connects "one volume to one device" (it shows up in the OS just as a SATA drive would, just more more flexible because you can use existing Ethernet devices and you can aggregate multiple connection into "one" big one). A NAS in it's simplest form (network shared folder) would be for access by multiple devices. – Albin Oct 08 '20 at 16:53
  • -1 Sorry, but with the latest edit to this question, this question went from being advice on SATA cable length to a shopping advice thread for USB 3.0 enclosures. Thus all of these answers are now extended discussions on shopping advice rather than something related to SATA cable length. Voting to close. – Giacomo1968 Oct 08 '20 at 17:39
  • @Giacomo1968 Although I disagree, thanks for your feedback! My view: For such a substantial change **after** answers have been submitted a new question should have been created (especially because the change is more of a partly answer then an addition to the question). Other users should not be punished for answering the initial question. Therefore you should down vote the question, not the answers. – Albin Oct 08 '20 at 17:54
  • @Giacomo1968 but I do agree with the close vote! – Albin Oct 08 '20 at 17:55
  • @Albin - Sorry about your answer was being downvoted. I think @ Giacomo has some misunderstanding of my _original_ question. I did mean **SATA hard disk**, but not SATA cables. In my original question, I did also suggested some possible solutions, including SATA to USB converter. I do not know why @ Giacomo is so surprised about discussing the SATA to USB converter in the second half edit, and considering this is a **_quick shift_**. – midnite Oct 08 '20 at 18:17
  • @midnite well, feel free to upvote ;). But seriously thanks for you comment, might I suggest myself, that you refrain from your "mild" shopping question (I think you essentially want to ask for some thing else)? But to answer it, you just have to try. As a general rule, the cheaper you go the less performance you get until it's starts to get unreliable as well. – Albin Oct 08 '20 at 18:38
  • @Albin - I really want to have this setup: 3.5" SATA HDDs sitting around 2m away from the PC, with stable connection. Currently my 0.5m + 0.5m SATA cable setup is already running but unstable. I want as few intermediate elements as possible. Fewer elements mean less likely to get a faulty device. And less slow down to the original transfer speed. No matter the solution falls into which type of cables, I will also ask about how to choose a stable cable. To be stable is part of the original question. Otherwise, I already have the setup running now, and I do not need to raise this thread at all. – midnite Oct 08 '20 at 18:55
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I'm using eSATA to connect multiple 5.25" Blu-Rays drives and I think this 2m length limit is wrong. I use only 30cm SATA and 50cm eSATA cables and still have problems. Especially if I connect instead a Blu-Ray drive an usual HDD. I think because my eSATA PCIe slot adapter is a passive device (and more plugs means more loss).

Finally I'm thinking about using an alternative solution which works really good in my backup NAS. This server's motherboard has only 4 SATA ports, so I bought a cheap 1 to 5 SATA Port Multiplier to connect more HDDs. I never had problems with disconnects although the HDDs are connected through usual 30 + 30cm SATA cables. Maybe this is a form of "SATA amplifier" as the circuit board must be connected to a 5V power source (USB or SATA Power).

If you use one Port Multiplier for each drive, it could be a solution for your problem. You could "glue" the board under your table and connect it to an usual usb power supply. With one drive there is no relevant overhead: https://wiki.odroid.com/odroid-h2/application_note/10_sata_drives

"With SSD, sequential I/O speed reaches 500 MB/s."

mgutt
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  • Thanks for reply. So surprised that I did not imagine SATA ports could be multiplied. But [this research](https://www.zdnet.com/article/are-sata-port-multipliers-safe/) suggests that SATA port multiplier may be not reliable. – midnite Oct 08 '20 at 16:58
  • This research shows only a problem (from 2013, nobody knows if its still present), where other drives suffer from one defective drive connected to the same multiplier. But my idea is, that you use one multiplier for each drive. You use it only as "SATA amplifier / extender". P.S. in my server I connected only two HDDs per Multiplier to avoid suffering from the Multiplier overhead ;) – mgutt Oct 08 '20 at 17:14
  • -1 Sorry, but with the latest edit to this question, this question went from being advice on SATA cable length to a shopping advice thread for USB 3.0 enclosures. Thus all of these answers are now extended discussions on shopping advice rather than something related to SATA cable length. Voting to close. – Giacomo1968 Oct 08 '20 at 17:39
  • @mgutt - I see. So it may be a consumer grade SATA single extender. By the way why no one makes such SATA signal repeater which makes my life easier. Back to your answer, I wonder if using a _multiplier_ can allow the total length to go beyond the 1 meter limit? As you are just connecting 30 + 30 cm which is still a lot below the length limit. – midnite Oct 08 '20 at 18:24
  • @Giacomo1968 You're right to downvote the question, but not the answer. I responded to the initial question and nothing else. If midnite removes his edit, everything would be fine again. – mgutt Oct 08 '20 at 20:10