Q: Best SSD internal drive for late 2009 27"?

Get the OWC

That depends on how much space you need, they are both good, and either will run at the bus limits (550 mb/s approximately, as will any other fast SSD)

Actually you will not get 550 in an 09 iMac, it (from memory) has a SATA 2 bus, so roughly half that.

HI, if the sata 2 bus speed only allows for 1/2 in the late 2009 iMac, would it be better and faster to use an external ssd or does it matter?

thanks!

An external would be significantly slower.

Thanks for the reply! Would the Sata 2 influence which brand of ssd to buy since its maxed at 1/2 Speed? im looking at OWC & Samsung. Also does it make a difference if I replace the hhd or use the optical slot and use an external cd drive?

I would never buy Samsung, especially as the OWC are excellent.

As all SSD are affected equally by the bus speed, it makes no difference.

As the external connections on a 2009 are so slow it would be a waste of your money to buy an SSD and connect it that way, so don't waste your money.

First, a late 2009 27" iMac is actually a Mid 2010 in disguise...

According to Wikipedia, it shipped with 1066 MHz speed memory, but supports 1333 speed.

https://en.m.wikipedia.org/wiki/IMac_(Intel-based)#Unibody_iMac

This would be my first upgrade.

Second, look carefully in System Profiler.  See if you can tell what SATA is installed, II or III.

I bet it has Sata III, 6G

I would give the Neptune drive a try.

https://eshop.macsales.com/shop/SSD/OWC/lineup

The computer also has a Firewire 800 port.  A nice external case with the old drive will be pretty fast.

Is it better to replace in the HHD slot or the Optical or does it matter. I read that the optical might only be SATA l speed?

I couldn't find where it says SATA ll or lll but from what I can tell, there are a lot of differences between the late 09's and the 10's and upgrade potential. I just want to make sure its worth replacing with an SSD or should I consider spending an extra couple of k's for a new one:-(

Even if it was SATA1 it would be worth it, but it's SATA2 so should increase disk access speeds by a factor of at least 5

From "About This Mac", then click on "System Report"

Note the "6 Gigabit" link speed...

The major problem encountered with 3 Gigabit controllers is the link speed could default to 1.5 Gigabit,

therefore either buy a drive which does 3 or 6 only (like the OWC Neptune), or buy a 3G drive.