Why SSD is slower than HHD

[novetan]

I was transfering 50 GB of photos to two different portable disks via a 2014 MacBook Air. And I can’t believed transfering to my newly purchased Crucial SSD took almost twice slower than transfering to my 6 yr old Seagate HDD. SSD was 22min and HDD was 12 min. I tested twice and consistently same result. Being a tech noob, I suspected it could be cable or connectors issue. Here’s the data

1) MacAir USB port A 3.0

2) HDD has USB 3.0 Micro B connection on the disk side, the other end is USB A 3.0.

3) SSD has USB C on the disk side. It comes with a cable with both ends type C. So I used an adapter USB C to USB A 3.0 for MacAir side.

4) Same SD card reader was used during both transfer with USB A 3.0

Where’s the problem. Can someone advise pls. Tks

 

[Bigwaff]

SSD has USB C on the disk side. It comes with a cable with both ends type C. So I used an adapter USB C to USB A 3.0 for MacAir side.

100% positive the adapter is same USB 3 as HDD connection? There is USB 3 Gen 1 (5 Gbps) and USB 3 Gen 2 (10 Gbps), which aligns with your speed differences.

 

[kschendel]

Is your SSD a SATA SSD? Does the USB enclosure you're using with it support UASP?

 

[Algr]

I had a friend who was sure he bought an SSD, and I had a hard time convincing him that SSDs don't vibrate or make clicking sounds.

 

[FreakinEurekan]

Possibly also your USB-C to USB-A adapter is the cause. Either only offering gen1 or even USB 2.0 speed.

 

[novetan]

Possibly also your USB-C to USB-A adapter is the cause. Either only offering gen1 or even USB 2.0 speed.

Is your SSD a SATA SSD? Does the USB enclosure you're using with it support UASP?

Er...no idea man. Below was the one I bought. As layman, its a SSD to me which shld perform faster than HDD

Crucial X9 1TB Portable SSD | CT1000X9SSD9 | Crucial.com

Buy Crucial X9 1TB Portable SSD CT1000X9SSD9. FREE US Delivery, guaranteed 100% compatibility when ordering using our online tools.

www.crucial.com

If you reckoned the adapter is the choke, how to check? The USB adapter is male Type A 3.0 blue colour. The female side is C. I don't see any adapter in the market has any marking. Type C is simply recognised by just its shape right? Or fake Type C?

Could it be the micro B connection cable to HDD is considered super speed? I saw google images describing micro B seems like come with super speed cable. But then the other end is USB 3.0

 

[novetan]

100% positive the adapter is same USB 3 as HDD connection? There is USB 3 Gen 1 (5 Gbps) and USB 3 Gen 2 (10 Gbps), which aligns with your speed differences.

My MacAir port is simply Type A 3.0

is there any point to get those gen 1 or 2. No right?

Both disks are limited by MacAir port. So both were put under the same constant test.

 

[novetan]

Possibly also your USB-C to USB-A adapter is the cause. Either only offering gen1 or even USB 2.0 speed.

The male is blue colour which denotes USB 3.0. The female is Type C shape. How else to check ?

I hv replied to one post abv my MacAir is port A 3.0. Any purpose of getting adapter of gen 1 or 2 for the male side? The choke pt still limited to 3.0 right?

 

[Basic75]

100% positive the adapter is same USB 3 as HDD connection? There is USB 3 Gen 1 (5 Gbps) and USB 3 Gen 2 (10 Gbps), which aligns with your speed differences.

Unless I'm mistaken 50GB in 12 minutes are about 70MB/sec which is well below the 5 Gbps of o.g. USB 3.

 

[Basic75]

That's quite slow, even for a shoddy DRAM-less QLC drive. You mentioned an SD card reader, have you tried copying from your Mac's internal drive to remove the SD card from the equation? Is the SD card reader on the same USB bus as the other external drive? You'll have to check the USB tree view in System Report for that.

 

[meson]

Er...no idea man. Below was the one I bought. As layman, its a SSD to me which shld perform faster than HDD

Crucial X9 1TB Portable SSD | CT1000X9SSD9 | Crucial.com

Buy Crucial X9 1TB Portable SSD CT1000X9SSD9. FREE US Delivery, guaranteed 100% compatibility when ordering using our online tools.

www.crucial.com

If you reckoned the adapter is the choke, how to check? The USB adapter is male Type A 3.0 blue colour. The female side is C. I don't see any adapter in the market has any marking. Type C is simply recognised by just its shape right? Or fake Type C?

Could it be the micro B connection cable to HDD is considered super speed? I saw google images describing micro B seems like come with super speed cable. But then the other end is USB 3.0

That adapter was a short term solution for a period of time before usb c. The right side of the adapter is a normal mini b connector and the left side is there to handle the extra power that is allowed to pass through for the usb 3 spec.

The hdd seems to be operating at normal speeds for it. The SSD should transfer about 4-5 times faster than the hdd.

Since you are testing, I assume your SSD is mostly empty. As an SSD fills, its write speed will slow down. Even then I wouldn’t expect results that poor. My old work issued MBP with 128GB would write at usb 2.0 speeds when it was about 3/4 full. Same with my M1 mini, speeds drop as it fills.

Is the usb c to usb c cable the one that came from Crucial? If not, it could be a power delivery cable not meant to carry data at high speed. I would recommend trying a usb c to usb c cable that mentions data speeds of 5 gb/s (usb 3.0) or higher. The higher spec’d ones are backward compatible. Or better yet, a single usb c to usb a cable, again, check for the data speeds.

It sounds like your adapter should be usb 3, but it’s another possible culprit. I’d go the single cable route though, if I’m buying new parts.

 

[chrfr]

If you reckoned the adapter is the choke, how to check? The USB adapter is male Type A 3.0 blue colour. The female side is C. I don't see any adapter in the market has any marking. Type C is simply recognised by just its shape right? Or fake Type C?

USB-C is the connector type. It can be one of several different specifications so it's likely that the adapter is the problem. You can verify the speed of the drive's connection through the adapter by holding down the option key and going to the Apple menu and selecting "System Information." Then look for the Crucial drive in the USB section, and you'll see the speed. If it's connected properly it'll show "Up to 5 Gb/s" but it's probably going to show "Up to 480 Mb/s", or even worse, "Up to 12 Mb/s."
You can get a proper USB-A to USB-C cable which will work fine, you just need to get one that you're sure supports USB 3.0. Something like this would work, but there are less expensive options: https://www.bestbuy.com/site/belkin...g-data-transfer-black/9511001.p?skuId=9511001

 

[Fishrrman]

(sigh)

STOP RIGHT THERE.

OP...
Before going any further, download the free "Blackmagic Speed Test" app from the Apple Store.
Run it on your drive.
Post the read/write results here.

That drive should give you reads around 900MBps and writes around 800-850 (or better).

What are you getting?

 

[chrfr]

That drive should give you reads around 900MBps and writes around 800-850 (or better).

This is not correct on a 2014 MacBook Air that only supports 5Gbps USB. Maximum speeds will be in the range of 500-600Mbps.

 

[klasma]

This is likely a QLC SSD, which are slow for sustained writes. If it’s many small files, it’s even slower. SSDs are fast for random access, but not necessarily for sequential writes.

Get an SSD like the following, it should be faster for your use case: https://www.apple.com/shop/product/HPQ42ZM/A/lacie-1tb-mobile-ssd-secure-usb-c-drive

 

[chrfr]

This is likely a QLC SSD, which are slow for sustained writes. If it’s many small files, it’s even slower. SSDs are fast for random access, but not necessarily for sequential writes.

Get an SSD like the following, it should be faster for your use case: https://www.apple.com/shop/product/HPQ42ZM/A/lacie-1tb-mobile-ssd-secure-usb-c-drive

Until it’s determined that the USB adapter and/or cable is performing correctly, there’s no point in buying a new SSD.

 

[Nguyen Duc Hieu]

I was transfering 50 GB of photos to two different portable disks via a 2014 MacBook Air. And I can’t believed transfering to my newly purchased Crucial SSD took almost twice slower than transfering to my 6 yr old Seagate HDD. SSD was 22min and HDD was 12 min. I tested twice and consistently same result. Being a tech noob, I suspected it could be cable or connectors issue. Here’s the data

1) MacAir USB port A 3.0

2) HDD has USB 3.0 Micro B connection on the disk side, the other end is USB A 3.0.

3) SSD has USB C on the disk side. It comes with a cable with both ends type C. So I used an adapter USB C to USB A 3.0 for MacAir side.

4) Same SD card reader was used during both transfer with USB A 3.0

Where’s the problem. Can someone advise pls. Tks

There problem is on the Crucial SSD.
When you copy a big volume, the DRAM cache (relatively small) on the SSD is soon occupied and greatly reduce the writing speed to the real read/writing speed of the NAND chips, which is merely 40~60MB/s, sometimes worse; while the HDD actual read/write speed is still be maintained at 80MB/s (max speed 140MB/s).

 

[Algr]

When you copy a big volume, the DRAM cache (relatively small) on the SSD is soon occupied and greatly reduce the writing speed to the real read/writing speed of the NAND chips, which is merely 40~60MB/s, sometimes worse; while the HDD actual read/write speed is still be maintained at 80MB/s (max speed 140MB/s).

Gah. It is crappy that just copying files the wrong way can cause this. Is there a fix that doesn't involve reformatting the drive?

I used to boot my old Intel mac from a SSD. When I tried to read or write to that SSD from my Studio, performance was dreadful: 5-10 MB/s despite USBc on both ends. I ended up reformatting the drive. Now I get 300 MB/s, but can't boot that old Mac from it anymore.

 

[Nguyen Duc Hieu]

Gah. It is crappy that just copying files the wrong way can cause this. Is there a fix that doesn't involve reformatting the drive?

I used to boot my old Intel mac from a SSD. When I tried to read or write to that SSD from my Studio, performance was dreadful: 5-10 MB/s despite USBc on both ends. I ended up reformatting the drive. Now I get 300 MB/s, but can't boot that old Mac from it anymore.

Of course. Therefore there are 2 commands to copy file in the MS-DOS era (still valid now)
1. copy => slow (this equal to drag and drop the files with your mouse)
2. xcopy => fast (Many apps use this method to do file transfer among disks)

Other command like diskcopy also result in higher speed.

 

[novetan]

Thank you so much for all the responses. For clarity, here’s two pictures (1 & 2) to reflect what I have done.

To following respondents

Chrfr:
The USB info stated two USB types (photo 5). Speed is 12mb/s. My iMac is 480 mb/s. I called up Apple to ask why such a big disparity. He confirmed my MacAir both left and right ports provide the same speed and is not 12mb/s. Otherwise it would hv taken 1.25 hrs to transfer and is clearly not the case. In fact I hv transferred the same file fr SD card to iMac and to MacAir and the latter took lesser time, probably because MacAir is SSD drive and iMac is Fusion drive. But this not the main point of discussion.

Fishrrman:
My old MacAir can’t install Black Magic. The abv timing shld give a clue which one is the winner.

Klasma:
It is a QLC. I bought at a very good price. I don’t need a super super fast speed so any SSD is ok for me. And logically no matter how lousy a SSD shld be faster than a HDD


BTW, I just did another experiment transfering 2GB (not to waste time using 50GB) of photos directly from MacAir to the two different disk. (photo 3 & 4). Again it showed HDD is faster than SSD (46s against 29s)

One last thing. The HDD cable is micro B. Some articles said micro B is known as superfast cable. Could it be micro B cable become faster than C cable? Personally I can’t believe it’s the case. Either the C cable that came with it sucks. But I also think that native cable should be almost always the correct one since it’s a branded SSD.

From my 2nd experiment, does it affirmed the choke point is the C cable and/or the poor quality of the adaptor?

Tks all again

 

[Basic75]

Now that's a lot of information, thank you for being thorough! That said, the 12Mbit/sec in photo 5 are not for the SSD or HDD, it's for a Mac-internal USB hub that connects a USB 1 Bluetooth controller to the USB 3 bus. Can you find the SSD somewhere in the device tree? It should have "Crucial" in the string for the Vendor ID.

 

[Basic75]

The HDD cable is micro B. Some articles said micro B is known as superfast cable. Could it be micro B cable become faster than C cable? Personally I can’t believe it’s the case. Either the C cable that came with it sucks. But I also think that native cable should be almost always the correct one since it’s a branded SSD.

Micro B comes in two variants, the small one that does up to USB 2.0 speeds (480Mbps) and the wider, two-part one that is USB 3 (5Gbps). A USB-C cable can be anything from USB 2.0 speeds up to USB 4/Thunderbolt 4. I agree that the cable that came with the SSD in 2024 should not be a slow USB 2.0 cable, that would be weird and crazy and stupid.

 

[Basic75]

Btw, you might be interested in this: https://support.apple.com/en-us/102646

 

[Basic75]

no matter how lousy a SSD shld be faster than a HDD

HDDs are very consistent with write performance, they can sustain their maximum performance forever. Unlike cheap SSDs once their SLC part is full. HDDs also have better data retention, especially compared to QLC. And you can rewrite the same sector as often as you want, not just a few hundred times. Cheap SSDs are mostly just that, cheap. Of course I wouldn't ever go back to an HDD for my main system disk, but that doesn't mean that SSDs are unequivocally better than HDDs, at least not the cheap ones. That said, you were writing to a new SSD, so wear levelling and garbage collection should not have interfered and the expectation would indeed be for it to outperform a laptop hard drive.

 

[tonmischa]

Sorry, I did not read through all the replys. Wanted to try to help you anyway.

Are you sure, that the USB-C to USB-C cable you are using came with the SSD?
There are USB-C to USB-C cables out there which are only built for charging. They will only give USB 2.0 speeds during file transfers.
USB 2.0 speed is about 40 MB/sec, which would match your "50GB in 22 minutes"
Have you tried another USB-C to USB-C cable?

EDIT:
Where did you get the USB-C to USB-A adapter from? Are you sure it is USB 3.0? (The blue color inside the plug can be misleading too. It might only refer to the power (wattage) of USB 3, not to the transfer speed.)

Others have suggested buying a quality USB-C to USB-A cable. I would like to "+1" this suggestion. Good luck!