If you are a Mac user, you might be wondering which file sharing protocol gives the best performance when using a network-attached storage device (NAS) such as Synology, or a NAS / Thunderbolt over Ethernet device such as QNAP. With macOS allowing one to choose between AFP, NFS, SMB and CIFS protocols, it is sometimes tough to make the proper choice, especially considering that some of these protocols have different versions that might perform differently. Add to this the fact that macOS itself might behave differently depending on which version of it you are running, and it can get quickly aggravating for many photographers out there who are simply trying to get the best out of their equipment.
I am currently in the process of reviewing another QNAP device, and while at it, I decided to test out all these protocols on the latest version of macOS Mojave 10.14.3 on my iMac Pro that has a built-in 10 GbE connection. The 4-bay QNAP device offers both Thunderbolt over Ethernet and 10 GbE connectivity options, so I tested both, although it turned out that Thunderbolt offered better overall performance, which is why I decided to stick with it instead of 10 GbE. In order to make sure that the 4-bay QNAP device performs at its maximum potential, I used fast 7200 RPM 4x WD Red drives configured in RAID 0 configuration. File System Analyzer within QNAP Diagnostic Tool showed that the volume’s potential was roughly 680 MB/sec read speed and 570 MB/sec write speed, which is pretty decent for four drives in RAID 0 configuration (with each drive potentially being able to do up to 180-190 MB/sec, according to HDD Analyzer). Nothing was changed on the iMac Pro from the configuration standpoint, with default /etc/nfs.conf, /etc/nsmb.conf and /etc/sysctl.conf files (if you are running an older version of macOS, you should edit the /etc/nsmb.conf file and make sure to add “signing_required=no” to the file or your transfer speeds with the SMB protocol will suffer greatly).
To make sure that my data is a bit more accurate and not just localized to a single NAS system, I also ran a similar test on an 8-bay Synology DS1817+ NAS with 10 Gbit connectivity that I reviewed last year. The Synology drives are in RAID 6 configuration, using 6 TB HGST 7200 RPM drives. Since Synology DS1817+ does not have a Thunderbolt connection, all tests were performed over 10 Gbit network. To make sure that I can get the maximum potential network speed, the iMac Pro, the Synology DS1817+, as well as the 10 GbE network switch were configured for 9000 MTU Jumbo frames. Let’s do a quick overview of each file sharing protocol and we will get down to comparisons and conclusions right after.
What is AFP?
AFP, which stands for Apple Filing Protocol, is a proprietary network protocol that was developed as part of the Mac Operating System. It was originally known as AppleTalk, but was later changed and renamed to AFP. Because it is native to macOS, it is the most compatible and the most feature-rich among all supported network protocols. It has built-in support for “Spotlight” search, Time Machine, Mac Aliases and Bonjour Services, which other protocols are not compatible with.
What is NFS?
Network File System (NFS) is a distributed file system protocol that was developed for use in Unix / Linux operating system environments. It is based on an open standard and has gone through a number of revisions and contributions from the Unix / Linux community over the years, from version 2 (NFS v2) all the way to the latest NFS version 4.2 that was published in 2016. Most modern implementations of NFS are based on version 3 and 4 of the protocol, with some systems providing support for 4.1 and now 4.2. macOS natively supports NFS v3 and NFS v4, although the support for version 4 needs to be manually enabled through the /etc/nfs.conf file, since the operating system connects to version 3 by default.
What is SMB / CIFS?
The Server Message Block (SMB) is a network file sharing protocol that was developed by Microsoft, while Common Internet File System (CIFS) is one of its versions. Similar to AFP, SMB / CIFS were developed as native protocols for the parent operating system Microsoft Windows. SMB also provides some specific features, such as network printing, shared folder authentication, file locking, etc. macOS has built-in support for SMB 1 / CIFS, SMB 2, as well as SMB 3.
In short, think of the three as Apple, Unix and Windows protocols. Each has its list of pros and cons, but for Mac users, AFP is typically the route to take.
AFP vs NFS vs SMB / CIFS Performance Comparison
Now that you understand the main differences between these protocols, let’s take a look at how they all compare when dealing with a lot of network and Thunderbolt traffic. Take a look at the below table that summarizes performance results I got from the 4-bay QNAP NAS / DAS:
| Protocol | Version | Seq Read Speed | Seq Write Speed |
|---|---|---|---|
| AFP | N/A | 649 MB/sec | 306 MB/sec |
| NFS | v3 / v4 | 551 MB/sec | 121 MB/sec |
| SMB | v1 | 161 MB/sec | 169 MB/sec |
| SMB | v3 | 652 MB/sec | 624 MB/sec |
I ran a total of 5 tests for each protocol and version and picked the best result.
As you can see, the worst performer here is NFS. While it did a decent job with read speeds, averaging around 551 MB/sec over 3 tests using a 4 GB file (with AJA System Test Lite benchmark tool), its write speed was quite terrible at 121 MB/sec. Despite the fact that AFP is a native macOS protocol, it was also disappointing in terms of write performance on the QNAP, although reading speeds were excellent. The top performer here is SMB v3 – I was able to get 652 MB/sec read and 624 MB/sec write speeds using this protocol, which was quite impressive. SMB v1 / CIFS is quite terrible overall, showing very poor read and write speeds, so it should be avoided at all costs.
Here is the screenshot from AJA System Test Lite for the above SMB v3 result:
And here is the screenshot for the AFP result:
After running these tests, I realized that perhaps the QNAP implementation of AFP was just poor, so I decided to repeat the same tests on a Synology NAS. Below is the summary of results from running the same test on the Synology DS1817+:
| Protocol | Version | Seq Read Speed | Seq Write Speed |
|---|---|---|---|
| AFP | N/A | 1105 MB/sec | 506 MB/sec |
| NFS | v3 / v4 | 590 MB/sec | 156 MB/sec |
| SMB | v1 | 75 MB/sec | 173 MB/sec |
| SMB | v3 | 1108 MB/sec | 547 MB/sec |
The Synology DS1817+ was able to get faster read speeds due to having more physical drives and as you can see from the above table, I was able to get over 1.1 GB/sec speeds using both AFP and SMB v3 protocols. However, the situation is a bit different when it comes to write speeds. Similar to the first table, the top performer was again SMB v3, demonstrating excellent read and write performance. AFP performed better on the Synology NAS compared to QNAP, but still lagged behind by between 50-75 MB/sec. I re-ran the tests several times with both 4 GB and 8 GB sequential read / write operations and the results were still pretty consistent, placing SMB v3 above AFP in general. SMB v1 should be avoided like a plague on the Synology – I could not get more than 75 MB/sec read speeds, which basically demonstrates that the implementation of this version is probably buggy.
Conclusion
Based on what I see from two different NAS vendors, it looks like SMB v3 is the best network protocol one can use in terms of overall performance on macOS, with AFP being the second best. Both SMB v1 and NFS should be avoided – they demonstrated rather disappointing write performance. If specific macOS features that AFP provides are important to you, then you should test both SMB v3 and AFP on your NAS device and see how each does on its own. For Synology, it looks like the performance differences are not very noticeable, but for anyone who uses a QNAP device, AFP robs almost half of the write speed, which is just too much…
I know this article is probably a bit too technical for our readers, but I still wanted to share it, as I believe one should use the best tool for the job. If you use a NAS in your environment, it would be great if you could share your results using similar tools in the comments section below.
it is surprising that the reults are that far apart. I would be curious, what the performance is for many small files.
Alexander, I am running a 4K test on the QNAP with both AFP and SMB protocols and will report my findings shortly.
Alexander, here are the results from SSD drives configured in RAID 0 on a 4-bay QNAP device:
SMB 4K random read: 20.13 MB/sec
SMB 4K random write: 14.00 MB/sec
AFP 4K random read: 19.98 MB/sec
AFP 4K random write: 8.36 MB/sec
Here are the results from 8-bay Synology:
SMB 4K random read: 20.16 MB/sec
SMB 4K random write: 27.74 MB/sec
AFP 4K random read: 30.58 MB/sec
AFP 4K random write: 9.52 MB/sec
It looks like AFP does a bit better with read speeds when reading 4kb files (on larger storage arrays), but suffers greatly when dealing with random writes. My conclusion is that SMB is still better for both sequential, as well as random IO.
“or a NAS / Thunderbolt over Ethernet device such as QNAP. With macOS allowing one to choose between AFP, NFS, SMB and CIFS protocols,”
Well an HIJKLMNOP to you too.
Bill, LOL, sorry for being a bit too technical on this one. I initially didn’t want to write this article, but thought some of our readers might benefit from it.
No need to apologize.
Thought you’d get a laugh out of it.
good one.
I sure did, thanks Bill!
Time to get a 10GBe card for my Synology! Did you use their one or buy one of the cheaper third party ones?
Also are you using a SATA SSD in you Synology as a cache drive, or 2 so u can do read and write caching?
Wfp, I used a third party Intel 10GbE card. Got it from Amazon and it has been working amazingly well – here is the link. I have it installed on two machines. For the Synology unit itself, I would probably recommend to go with the approved list of cards, just to make sure that you are not dealing with driver issues. I believe the card I linked to works on the Synology NAS as well, since it is a generic card with an Intel X540 chip in it.
In regards to doing an SSD drive for caching, be careful and measure your performance before investing in one. Some people reported caching issues and potentially decreased performance. It all depends on your load and what you are trying to do. Generally, a read cache is going to accelerate read speeds, but be careful about doing read + write caching – you do not want to corrupt your RAID volume.
Thank you for the article. It looks like you used the SMB screen shot graphic twice however, the second time assigning it as the AFP results.
Steve
Stephen, thank you for letting me know. I thought I cleared the cache, but it looks like something odd happened. You should be able to see the correct image now.
Thanks for this, very useful to know as I always wondered which performed best in speeds. However there is another factor to consider too, and one which I haven’t resolved, which is the reliability of the connection.
I often find that on my iMacPro or MacBookPro, to my Synology NAS 1618+, that it will drop all the network drives periodically. Usually after waking up the Mac is when they disappear, but not always. It’s such a frustrating problem. I have switched between SMB and AFS and still observed it, but it’s worse on AFS.
Simon, I also experience similar issues with a mapped connection. I often find myself remapping the share using CMD + K command, which is kind of a pain – I wish the connection stayed persistently. This happens both with AFP and SMB connections unfortunately.
Thank you Nasim for this article! While it’s surely a bit on the technical side, I find it very useful!
Hi Nasim, SMB v3 is a big step and speeds up network performance impressively. – But if you really want speed there is no way around NVMe. And since prices dropped significantly this is the choice to do. I’ll get a SSD 970 EVO NVMe M.2 2280 2 TB for under $ 500. Read/write performance and (also important) access time is unbeaten: sequential read or write is above 3 GB/s (for the models bigger than 1TB). A customer of mine, a film producer, was looking to process 4K-Videos which average in size (in his case) of about 20 – 30 GB each.
Cheers! -jan
I’ve ben able to achieve faster writes with AFP, using Kernel Tuning (in sysctl.conf) and asynchronous I/O (using aio) on my NAS. These settings allow more files to be opened at once:
kern.maxfiles=25600
kern.maxfilesperproc=16384
net.inet.tcp.sendspace=65536
net.inet.tcp.recvspace=65536
Asynchronous I/O cam be enabled in the boot loader configuration file: aio_load=”YES”
Almost ever server need some tweaking under the hood!
Best,
Ben
Using AFP network protocol my Synology DS1618+ with four 6GB WD Red drives achieves 492MB/s write and 915MB/s read. Plenty of speed for my use cases.
PS: In appreciation of the information your site provides, I navigated from your site to the vendor to purchase the gear. Thank you for all you do!
Thank you Bob! If you try out SMB, you can probably get close to 550 MB/sec write speeds on that little beast!
Thank you, Nasim, for this very specific and targeted article about NAS and the different systems. I have used the Synology 218Play 2 blade server to back up my LR images and catalog on a 1 TB Samsung external SSD for about 3 1/2 years. I have just upgraded to the Synology 218+ 2 blade server and have been looking at how to set it up, and also migrate everything on my 3 1/2 year old external SSD to a new SSD, keeping the same external drive name the same, so my image won’t disappear from LR. Will just have the WD Red HDD’s scrubbed and reinstall in my new server. I think they are more reliable that an SSD over time and the SSD sometimes “disappears” as was mentioned above. A friend of mine, Cisco certified IT person, said the SSD’s wore out fast than the HDD’s, which is why I want to replace mine. OSX Mojave 10.4.13, the version I have, in Disk Utility, offers a way to format the HDD’s in a RAID system, and then I just turn on Time Machine on my Mac Pro to initiate backups.
It is so great to have all you techies around to help me decide the best way to upgrade my backup. Thank you.
This article is lacking a time stamp. It is rather irritating when articles lack a timestamp as then it is hard to assess their validity. Luckily, the comments are recent, so probably this article is pretty current.
First, Nasim, THANK YOU for this article. It was exactly the type of information I was looking for as I set up my new/first NAS.
To: Jon P: agreed about timestamps, always bugs me too; but there are a few clues at least: like you say, the comments are recent (oldest is March 5, 2019) and if you look at en.wikipedia.org/wiki/…e#Releases you’ll see that 10.14.3, which the author mentions and calls “the latest”, was released Jan 22, 2019 and replaced by 10.14.4 on March 25, 2019, so a relatively narrow window, especially once you apply the comment cutoff of March 5. So between Jan 22 and Mar 5, 2019. If you look at the source (yes, I’m that crazy) or open one of the pictures in the article in a new window/tab, you’ll see in the URL of the picture that it was uploaded in “2019/03”, so I suspect the article was released between March 1 and March 5, 2019.
Hi Nasim,
I just bought a Synology 918+, set it up in Raid 5 mode, and was wondering about all of the protocol settings and ran across your article and site (which I immediately signed up for). I don’t think this is too technical at all. I think that mot people that are on this site are already self starters and doing their own IT. Super helpful to me and I appreciate you taking the time to peck this thing out. Cheers.
thanks for this article that helps.. I have a QNAP TVS-882ST2 (8 bay SSD)
Migrating to High Sierra, I stumbled over writing speed close to 0 .. whatever protocol I used. All 3 are activated on the shares.. I’m trying to figure out if AFPS is the problem.
Fantastic article- I wonder if you might follow up with a short list of recommended NAS devices for Mac users, who intend to back up occasionally to the NAS and use it for data retrieval while on the road away from their offices? Hard to choose- especially not knowing about performance limitations, etc.
Re: Connection reliability, we’ve experienced a marked drop-off of this since several users on our lan-connected NAS (4-bay QNAP in RAID 10) upgraded to mojave. It is visible in the NAS web admin connection log, with some users serially reconnecting (“Login”) every second(!) for extended periods. Worse still, they also drop (“Logout”) at inopportune moments — occasionally causing lost work.
An older iMac, maxed-out on High Sierra (10.13.6) connects only once, and the connection just stays up.
The QNAP has the original firmware from 2014, from what info I’ve been able glean from the support forum, AFP reliability hasn’t improved since, and I operate on a strictly ‘not broken don’t fix’ policy — and I’ve certainly read plenty of firmware-upgrade-gone-wrong horror stories on said forum.
Frustrating, because it was until recently rock-steady across the board, and difficult to troubleshoot. I’m inclined to blame mojave networking and/or upgraded software ‘auto-save’ behavior (specifically MS Office and Adobe CC), because the problem seems confined to the new macs.
Do you have any thoughts on this issue, is it something we’ll just have to live with?
Were writes synchronous on the nfs server? I know sync writes cause quite the slowdown. A “fix” on zfs based systems is to use a fast slog to help it along.