Overprovisioning

One of the most interesting things to consider when grabbing an SSD for your Power Mac G5 is the concept of overprovisioning.

It’s a confusing concept – but here it is in a nutshell.

Hard drives and SSDs don’t really have a delete command. Instead, when the operating system is told to delete a file, it marks a table saying this place in the hard drive is empty. For traditional platter hard drives, this just meant the OS telling the hard drive to write the data in that certain place. Everybody was happy.

But with SSDs, things get tricky. SSDs use NAND flash memory which cannot be easily written over like traditional hard drives. They must be first erased for the new data to be able to be written. So, theoretically, a SSD could fill up to 100% capacity and not be able to write any new data at all, even your operating system caches and page files and what not. When that happens, the SSD takes a serious nose dive in performance. To counter this, SSDs tend to have support for things like TRIM, which tells the SSD to put certain spots of the drive into some sort of garbage collection. Quietly in the background, the SSD will erase those blocks that are empty so data can be written and read at a normal, brisk pace.

More good news – almost all SSDs are built with some overprovisioning, meaning that some space of the drive is set aside as clean empty space for things to get shifted about when stuff is getting deleted and organized.

Here’s the bad news – Power Mac G5s do not have TRIM support via our now dated operating system choices of Tiger or Leopard. Without TRIM, your SSD bears the risk of running ragged in its performance, especially if you max out the drive with data. With every block having been written (if you do max it out), there is no mechanism to tell the SSD to free up deleted space even if you get rid of all of those apps, movies, games, and so on. This is the problem of using a SSD in a system without TRIM support.

In response, it is possible to overprovision even more than factory standard. You do this by first deleting the drive via a secure erase in Disk Utility. Then you create a partition that is smaller than the capacity of the drive. I hear 10-20% is often recommended. A 240GB drive might then look like a 220GB drive on your Mac. The extra space is then seen as not used by the operating system and always empty. Even when your SSD gets close to full, there will still be free space for the SSD to shift things around and keep its somewhat zippy performance up. If you do fill the hard drive to the brim, you may still see performance degradation but it may not be as severe.

There is a lot of debate about this. Many SSDs have some other built-in features to counter a lack of trim. Sandforce drives in particular have some pretty aggressive garbage collection, so you shouldn’t see degradation at all unless you really just torture that drive. That’s why I’ve seen Sandforce drives as the top recommends for G5s, especially the Intel 520/530 series. Even without overprovisioning (beyond factory settings) or TRIM, it’s likely that you may never see performance degradation for a long time. By a year or two, it might be time to upgrade your SSD anyway, right?

Here’s some additional reading:

– Nathan

iTunes: How long?

iTunes

Apple just announced the iPhone 6, and with it, a new version of iTunes (11.4).

All of this raises a question – how long will iTunes keep working for us PowerPC users?

It’s a darn good question, and unfortunately, there is no easy answer. Right now, iTunes (10.6.3) is still the de facto music player on your G5. You can buy music (even getting the new U2 album for free evidently). Music Match still lets you upload your music into the cloud to play on your various devices. That’s pretty cool.

But other new features are done. I doubt you could sync your iPhone 6 with the old iTunes. There is no fancy digital album experiences, no iTunes radio, and so on. This software has got an expiration date, for sure – but when? For how long? Only Apple knows.

I do recommend Music Match if for no other reason than it makes a nifty backup for your music in the mythical cloud. In case, iTunes suddenly quits working and your PowerPC dies a horrible death, you could still grab your music from Apple’s servers to place on a newer machine. It’s an easy way to back stuff up.

In the meanwhile, are there other workarounds? I have no idea, although open source audio/video players can probably rock whatever content you desire. That’s not really the problem, though. iTunes’ expiration is really tied to its still working access to the store and limited cloud features. When those go, the music player will still work – you just won’t be able to buy music like you once did.

Oh, and by the way, the classic iPod is dead. A moment of silence please.

– Nathan

Archived site updates

  • 5/6/2014 – I added a great link from TenFourFox to the Hardware page and a few tidbits of information on the Internet page. RSS feed to come.
  • 3/1/2014 – Quick morning updates to the Internet page. Read about a great workaround to speed up WebKit if you are having issues.
  • 2/28/2014 – First updates. Added more information about SSDs and liquid cooled G5s to Hardware page. New link at the bottom. And more information about opening .docx files on the Office page. A PDF section too with more links. Awesome!
  • 2/25/2014 – Site goes live.

I think I’ve got an RSS feed

It’s sort of ugly, but I’ve integrated an extremely simple blog script into the site and should be able to add updates and then create an RSS feed out of them. The RSS feed will be posted in the menu of the site and on the frontpage for your viewing pleasure. However, each time I add a blog post, I will have to regenerate the feed. Clumsy – but it was better than trying to rebuild the entire site in WordPress or something.

In G5 news

My G5 is plugging along fine, although I am in the market for a larger SSD like an Intel 530. I am getting nervous that my SSD is going to hit a brick wall since I never did over provision it during setup. I may do a fresh reinstall first until a new SSD falls into my lap.

Saulo is going to provide some video links to his G5 running dual SSDs. He says he tried them in RAID 0 but found no noticeable speed improvement over a single SSD. That matches what I have learned from others – even on newer machines, RAID 0 is not necessarily worth it unless you are doing some serious data crunching/caching.

-Nathan