2008 White MacBook with 240GB SanDisk Extreme SSD Slow Read/Write

[Maverick1337]

I just installed a SanDisk Extreme 240 in my 2008 White Macbook and I know that I'm limited to SATA II speeds so I won't be seeing ~500R/W speeds like people report. However, I have done some benching and I'm only getting ~120MB R/W speeds and I feel that's really slow. I don't know if it's because I just installed it yesterday and it needs some warming up or what but I am a little worried. Does this sound weird to anyone else?

 

[robvas]

What are you measuring read/write speeds with?

Sandforce drives will go faster when working with data that can be compressed - you see 500MB/s in the benchmarks, but that's reading/writing all 0's. If you write truly random data that can't be compressed, you'll see much lower numbers.

You should see from 160-200MB/s on incompressible data, and real-world data should be in between those two.

But first, are you sure your drive is running at SATA II? My 2008 Macbook defaulted to SATA I (1.5GB/s). Here were my speeds (120GB OCZ Agility 3):

I used the OCZ SSD toolbox to force the drive to run at SATA II (3.0GB/s), these were the new numbers:

BlackMagic Speed Test uses random data so the numbers aren't going to be as high as the will be in other benchmarking programs.

To check this, look up your Negotiated Link Speed in System Information, under 'Serial ATA'

Read more about it here:

https://discussions.apple.com/message/18725282#18725282

 

[Maverick1337]

I used BlackMagic and AJA to test and I just noticed that I am locked to SATA I speeds. Can I use the OCZ software to force it to SATA II speeds? Why is it defaulting to SATA I in the first place? Thank you so much for the help by the way; I really appreciate it.

Also, my link speed is 1.5Gb and my negotiated is 1.5Gb, does that mean I'm stuck on SATA I speeds?

 

[robvas]

I used BlackMagic and AJA to test and I just noticed that I am locked to SATA I speeds. Can I use the OCZ software to force it to SATA II speeds? Why is it defaulting to SATA I in the first place? Thank you so much for the help by the way; I really appreciate it.

I think you'll need to see if Sandisk offers a similar program. This link makes it sound like they don't offer one. Maybe there is a hack you can do in OS X (if it isn't an actual hardware problem).

http://forums.sandisk.com/t5/SanDis...Link-Speed-1-5G-instead-3G/td-p/276288/page/3

Even if you're stuck with SATA I, you're way ahead of where you were with the old HD.

I had a Kingston drive with a JMicron controller before this drive - and didn't have this issue. I could hit over 200MB/s. So maybe it's SandForce-specific.

 

[Maverick1337]

Well what's worrying me is that my Link Speed is 1.5Gb/s and Negotiated Speed is 1.5Gb/s, does that mean I only have SATA I in my laptop? It's a Macbook4,1.

EDIT - Did a little researched and discovered my Macbook is actually on SATA I not SATA II like I thought. Oh well, well I'm glad I don't have an "issue" of it running slower than advertised. Thanks everyone who answered.