- Jul 29, 2014
- Gigabyte GA-Z87X-UD5H
- RX 580
- Classic Mac
- Mobile Phone
I use a network macs to share media over SMB and haven't run into problems with speed limits limiting my media for a single stream. However I have seen macOS SMB deliver woefully sporadic data rates. And it's pretty hard to know where the problem resides. This dialog reminded me of a recent article with a surprising take on macOS I/O rate-limiting — I have no idea where else to here to post this news and I thought of it in this context, so here it is...
This explains a problem that I have seen for at least a decade when using macOS to make full drive copies using ddrescue: using the drive block device as opposed to the character device (/dev/disk2 vs /dev/rdisk2) caps throughput at about USB2 speeds (30MB/s). I discovered by accident that the character device doesn't suffer this.
Assuming the writeup above is correct, we can only imagine at what applications such a rate-limit bug might affect.
A few extra notes, in case anyone might find it helpful.
I'm experiencing a variety of small issues (mainly slow network speeds) which are making the network less practical than hoped. The main appeal were the $0 cost and "convenience" of converting an existing Hackintosh (with a large, quiet, and cool case) into an external hard drive.
The upsides of a Mac server:
• It works.
• It's free.
• It's a tidy solution (all my disks are in one quiet, cool tower).
• The two Macs play nicely together: I can screen share the Hackintosh on the MacStudio, using the same wireless keyboard, trackpad, and mouse, as easily as any other desktop.
• shuffling data between disks on the network computer is, of course, fast and easy.
So the network is a great solution for backup and storage. But it's slow transferring large files or directories (photography, videos, etc.). My main friction is photography. [FN1]
• Speed. It's *very* slow (much slower than advertised/expected). See below.
• Setup time. It takes a while to figure out how to set up a network, get it working, etc. This is far more time and trouble than just buying an external drive case.
• Other options are faster and not that much more expensive.
• Time Machine isn't the same over a network. It creates a .sparsebundle file instead of the usual .backups (?) folder. I think it's like an ISO; you can't directly access the files inside it like you normally can. Also, network drives won't save prior versions of files -- or something like that.
I have a 1Gbps ethernet card on my Hackintosh server. Speed tests say it's ~980 Mbps or 122 MBs/second. At that rate, a 1GB file should transfer in ~8 seconds. But real world tests are *much* (2-5x) slower:
1GB file → 41 seconds
Server→Computer: 52-63 MBs/second.
1GB file → 18 seconds
A 10Gb network card seems like an obvious upgrade.
It *should* be 10x faster with a direct connection. But that depends on what's causing the slow-down. It would cost another ~$100. And I'd sacrifice internet speed, as the [Server→Router→Computer] setup gives me much faster wired internet ~200-300Gbps vs. WiFi ~80-100 Gbps. (The router ports are 1Gbps)
1. A 10Gbps (1,250 MBs) network card is about ~$100. That should theoretically improve speeds by 10x. Even a 2x-5x speed increase would match the speed of the HDDs, matching the speed of the HDDs. 10x would match the SSD speeds.
But that assumes the current much-slower-than-expected speeds are caused by the connection.
2. A docking station (TerraMaster or Sabrent) can run from $170-$280. That's $78-$180 more than a new network card. It would largely skip the network, potential 10Gbps speeds (hard drives will capped by their own speeds, i.e. ~1Gbps for HDDs, ~5Gbps for SSDs), and avoid network-related issues like Time Machine.
3. A Thunderbolt bridge between the two computers is theoretically possible. But from what I've skimmed, it's very difficult to get a Thunderbolt card to work on a Hackintosh. And it would probably run ~$145.
4. An M2. NVMe SSD & an enclosure is also a tempting. It would expand *fast* drive space that is directly accessible by the computer at high speeds (10 Gbps / 1,250 MBs), moving the main bottleneck from the server to the Mac. The server could then be used mainly for bulk backup and storage, where speed would matter less.
The main downside is cost. A 2TB MVMe drive is $200-$240, plus $40 for a drive capable of 10Gbps transfer speeds. Some are as fast as 40Gbps (~5,000 MBs/second), but cost $150.
[FN1] Photography. For the most part, the primary need is storage, not speed. I have over 2TBs of photos, so they can't all fit on my 2TB Mac Studio. Some files are as large as ~1-2GBs. A single subject like a vacation (which I would edit at one time) can be upwards of 200 GBs. So current network speeds won't work.
*** Note: much of this hassle is due to the high cost of Apple's SSD storage. I have a 2TB Mac Studio. 4TB would have held all of the data I need fast access to. But increasing that to 4TB would have cost $600. smh