iTunes slow to read from SD Card in Macbook Air

[diegov]

I've recently bought a Macbook Air and I'm using a 64GB SD card to store my iTunes library there, so iTunes is constantly reading from the SD Card. The first times I used it I was quite disappointed, as there was a very important (1-2s) delay when switching between songs, which doesn't happen for example in other computers or my car which has an SD reader slot. However, the other day for no aparent reason the SD card was behaving incredibly fast, switching songs was instantaneous, but today I'm back to the old slow speeds.

Is there some reason why the SD card is fast or slow to read in different scenarios? I haven't plugged in anything to the USB port that could be hogging the USB bus.

 

[paulrbeers]

Are you sure it is due to the memory card reader or could it have to do with the system as a whole? i.e. Running out of memory, cpu busy, etc... ?

 

[diegov]

Memory and CPU seem to be ok, I've got like 1GB free RAM and CPU is under 10%.

I also get jerky movement when scrolling up or down with the arrow keys on the itunes song list, it's scrolling ok, then it freezes (all of itunes freezes) for 1-2s and then it resumen scrolling.

 

[diegov]

The jerky movement while scrolling was being caused by the Itunes sidebar, I disabled it and now I can scroll perfectly well. I still get an important lag when changing tracks.

 

[Consultant]

It's not iTunes, it's not the MacBook Air.

The problem is the memory card, which has high latency.

 

[diegov]

This doesn't happen in a PC nor in my car, it's instantaneous in all those other places. The SD Card is a Class 10 memory card.

 

[diegov]

Ok, I've isolated the problem and it only happens with mp3 files, not with AAC files. This is incredibly annoying because 90% of my music is in mp3 format. AAC plays immediately with no lag whatsoever :S

 

[jdechko]

Ok, I've isolated the problem and it only happens with mp3 files, not with AAC files. This is incredibly annoying because 90% of my music is in mp3 format. AAC plays immediately with no lag whatsoever :S

So convert all of your music files to AAC?

 

[JCMiller23]

I've had the same problem. I read on another forum that reformatting the SD Card to HFS+ (Mac OSX Journaled Extended) will solve this problem. About to try it here...

 

[siddharth3.14159265]

sd cards are inherently very slow, giving you even worse performance than a hard drive something like 10-15 mb/s write and 20-30 mb/s read. it is very likely because of that only.

 

[Boyd01]

Notice that this thread is 4 years old. I used to have a 2011 MBA and the SD card slot was really slow, regardless of card type. The slot on these older machines was actually connected to the USB 2.0 bus. In 2012 Apple changed the design and gave the card slot a much faster interface.

 

[Dweez]

My 2013 MBA is still "relatively slow" when using an SD card. 700 meg/sec read/write to internal storage, 60 meg read & 85 meg write to the SD, formatted either hfs or exfat. Sure, it's an old thread but what the heck?

 

[Boyd01]

That's not too bad for a SD card. But put that same card in a 2011 MBA with the USB 2.0 interface and you should top out at only 30MB/sec.

 

[JCMiller23]

After switching the formatting of the SD Card to OSX Journaled everything (in itunes) runs (99%) smoothly. Hardly notice any difference from keeping the (90 gigs worth of) songs on the SSD. Specs: 2011 MBA (A1369) and card is PNY 256 gb SDXC Class 10.

 

[Boyd01]

Have you tried it with video? I think you will notice the difference from the SSD in that case.