Archiving data: DVDs, flash drives, hard drives?

▼ Originally, I intended to write a story under the title "saying goodbye to the optical drive". But after a few minutes of research, it turns out that, in my particular case, the optical drive may be on its way out, but it hasn't quite left the premises yet, and not just because I may need to rip a DVD or CD once or twice a year. Let me tell you a tale of backups and storage management.

I think my first USB flash drive was 128 MB. (Yes, that's MB, not GB.) And my first CompactFlash card 16 MB. So when I got my PowerBook G4 back in 2003, being able to burn a whopping 4.5 GB to a DVD was huge.¹ Back in those days, there was no Time Machine, so I'd often burn important data to DVD to back it up. I also got in the habit of burning video files of stuff I may want to rewatch at some point to DVD, as well as other types of files that I want to keep but don't necessarily need to have on my internal drive. So over the last decade I amassed seven containers with about 20 burned DVDs (or CDs) each. So that's over half a terabyte worth of data.

Then, in 2007 we got Time Machine, which backs up your internal drives to an external one. So with backups out of the way, the question is: where do I archive data that I can't or don't want to keep on my computer's internal drive?

Burning DVDs

In theory, you can burn (write) data to a DVD a bit at a time. In practice, you burn an entire DVD at a time. So you first need to collect all the files that you want to burn, and then it takes about 30 minute for the actual writing and another 15 or so for the system to check whether all the files were written correctly. DVD-Rs and DVD+Rs are slightly different kinds of recordable DVDs, but I think all DVD burners support both types now. They hold about 4.5 GB¹ and can only be written once. There's also dual layer DVD+Rs that hold about 8.5 GB, but they are a good deal more expensive and the burning is a lot slower. There are also DVD-RWs, which you can erase and use again for something else, but they're notoriously unreliable.

So burning DVDs is pretty inconvenient—even before optical drives started to disappear from Apple's computers. These days, you have to buy a separate USB Superdrive (or third party external DVD drive) to read and write DVDs and CDs. However, there is a big upside: they're pretty cheap. If you buy them in bulk, you can get them for as little as 20 cents a piece. Speaking of bulk: a DVD weighs about 17 grams. That's not a lot, but I keep them in containers that hold about 20. Those end up weighing about half a kilo for about 100 GB of data.

If you want to stick with optical disks (discs, whatever) for your own use, then you may want to look at blu-ray. But especially in the Apple world, few people can read them.

External hard disks

Hard disks are everything DVDs aren't. You can just write data without thinking about it, erase, write something else, no problem. And they're fast. HDDs have been limited by the speed of the USB 2 bus for a long time now. I'm very interested to see how fast my latest 2.5" USB 3 drive performs once I get a computer with USB 3. External HDDs have also gotten pretty cheap: that 1 TB one cost me 60 euros.

External HDDs have two downsides. Because they're so big, that's a whole lot of eggs in one basket. And even though they're fast, it still takes hours to transfer all that data, making it hard to make extra copies. The fact that there's an extra box tethered to your laptop all that time doesn't help.

But at least the 2.5" models that get their power over USB are infinitely better than the 3.5" models that come with their own power brick. I had three of those, but in each case either the power brick or the enclosure failed after some years. The drives themselves are fine though, but now I need one of these to use them. Also, the 3.5" drives are more than half a kilo, while a bare 2.5" drive is only 100 grams, 170 grams in the USB enclosure.

Mac - Windows compatibility is also an issue. I formatted my first USB HDD with the FAT file system, which both MacOS and Windows can read and write. But then I accidentally switched the power off, which corrupted the FAT so that new files started to overwrite old ones, so I lost a lot of data without knowing it. So you really need the journaled HFS+ file system, but then you lose Windows compatibility. (And FAT can't handle files larger than 4 GB.)

USB flash drives and SD cards

A year ago, I was shopping for USB flash drives and SD cards, and I thought that it wouldn't be long before those would be so cheap that they're a good alternative for DVDs. But at about 50 cents a gigabyte, we're not there yet.

USB flash drives are even more convenient than external HDDs: they have no moving parts and they're tiny, so they're easy to carry and when connected, don't get in the way of using a laptop. They can be fast, but especially older ones may be slow. You can get 128 or even 256 GB flash drives now, but to avoid the eggs/basket issue, you can also get several smaller ones. Avoiding the biggest and the smallest available gives you the best price per gigabyte, but on the other hand different sizes can be convenient for different things. For instance, I may want to make a copy of my photo library that's 90 GB on a 128 GB drive. Four 32 GB drives wouldn't work so well for that.

USB flash drives are especially useful for exchanging data with other people, or even with devices such as TVs and audio systems. However, for most other uses I prefer SD cards, because they provide a more consistent experience than USB flash drives that come in all kinds of weird form factors. It's also easier to find out whether an SD card is fast or not so fast before you buy it. With USB flash drives I'm reluctant to reformat them as HFS+, because I'm not sure I can format them in a way that allows other systems to read them. With SD cards this is not an issue, I can simply reformat those as FAT in my camera. SD cards weigh almost nothing at less than 3 grams. Another nice little feature on SD cards is the write lock switch.

Conclusion

Let's compare the different options:

	$/€/TB	Weight/TB
DVD±R	45	5 kg
2.5" HDD	60	170 g
3.5" HDD	35	310 g
USB flash	370	150 g
SD card	520	90 g

So burning data to DVD is still one of the cheapest options—but only if you buy DVD-Rs or DVD+Rs in spindles of at least 50. And then you have to figure out how to store them. I've already copied a lot of that data on DVDs to a USB HDD, but I was thinking about having the second copy² on SD cards and get rid of all those DVDs. But considering the price of half a terabyte worth of SD cards, that can wait.

¹ It's really hard to find out how much data fits on a recordable DVD, due to the multitude of definitions of the gigabyte, rounding at various stages, general sloppiness and the need to inflate numbers for marketing purposes. And then there's the file system overhead and a little extra overhead that Apple imposes. But it's not all that meaningful anyway, as you'll rarely be able to fill up a DVD exactly. So I'm using 4.5 GB as a nice, round number.

² Data doesn't exist until it exists in two places.

Permalink - posted 2013-10-14

2013, a good MacBook Pro year?

▼ I bought Apple laptops in 2002, 2003, 2007, 2008 and 2011. So that's one every two years on average. In 2008, I learned the hard way that I really need to have a decent backup computer in case my primary one fails. So a while back I decided that I should probably buy a new computer every two years, and keep the previous one as a backup for another two years. So I'm due for a new laptop this year.

Which brings up the question: is 2013 a good year for buying a new Mac laptop?

One important consideration is CPU speed. The good people over at Primate Labs have compiled a long list of results for different Macs running their Geekbench benchmark. What's interesting here is that single threaded performance for the highest end MacBook Pro increased by 70% between mid-2009 and late 2012. In addition to that, in 2011 the 15" MacBook Pros went from dual core to quad core, which obviously improves multithreaded performance quite a lot. But since then, the speed improvements have been rather modest.

But there's more to life than just a fast CPU. Such as fast I/O. So I went to support.apple.com and looked up the tech specs for the MacBook Pros released since 2006. By 2007, the MBPs were fully 64-bit capable, supported 4 GB RAM, had Firewire 800 and 300 Mbps Wi-Fi. In 2009, the Expresscard/34 slot was replaced with an SD card slot, and the RAM ceiling went to 8 GB. In 2011, the Wi-Fi speed reached 450 Mbps and Thunderbolt was added. Last year Apple added USB 3, and we saw the new high resolution, slimmed down MacBook Pro with Retina Display.

Once we got to see the new MBPwRD (or rMBP or high resolution MBP) last year, it was obvious that this was the future of laptop computing. Or all computing, really: it won't be all that long until all computer screens reach "retina" resolutions. However, the MBPwRD has a few important weaknesses. One is networking. The 300 Mbps limit on my mid-2011 MacBook Air is a frequent source of frustration: transferring files over my home network at 22 MB/sec (on a good day!) is no fun. The MBPwRD should be about 50% faster, and you can plug in the Thunderbolt-to-GE adapter without losing your external screen. But 1.3 Gbps 802.11ac would be really, really sweet.

Speaking of external displays: apparently the MBPwRD can handle two (three?) of those... but only at a resolution of 2560x1600. So either you get to use the built-in high resolution screen, or you can use a nice, big external low resolution screen. Thunderbolt 2 should allow for 4k resolutions on external screens.

In addition to faster Wi-Fi and Thunderbolt 2, based on this year's MacBook Airs and iMacs, we can expect updated MacBook Pros to have better battery life and very fast PCIe-based SSDs.

So for those of us who are still on 300 or 450 Mbps Wi-Fi, USB 2, and low-to-average resolution screens, the new high resolution MacBook Pros that we all think are coming soon will be a very solid upgrade. Apart from the high resolution display and faster Wi-Fi, I'm also looking forward to much better external HDD performance over USB 3. Sure, a Thunderbolt-connected SSD array is going to blow a 2.5" USB 3 drive out of the water, but then again, that USB 3 drive only costs 60 euros and it should still be a good deal faster than its USB 2 predecessor.

On the other hand, Intel's broadwell architecture is coming (although likely not until 2015) and maybe next year will be the year of the MacBook Air with Retina Display...

Permalink - posted 2013-10-09