Wednesday, April 16, 2008

Interview about Rhino

Floyd Marinescu interviewed me about Rhino at the JAOO conference in Aarhus, Denmark last September. You can watch the interview here. Yes, I know I said "scratch to itch" :-)

I actually stepped down from the Rhino maintainer role since this interview was shot, although I do remain with the project as a committer.

Wednesday, April 09, 2008

Airport Extreme disappoints

UPDATE: Apparently, firmware upgrade 7.3.2 fixed the disk access problems. I'm now able to use a USB-attached disk to AEBS just fine. Skype also started working fine some time ago (even before the firmware upgrade). The speed issue (not being able to exceed 8 Mbit/sec on 802.11g with all-Apple equipment) unfortunately still remains.

I got a brand new Airport Extreme Base Station (AEBS) this Friday. (Kirk hauled it for me from Las Vegas to Hungary - Apple gear costs roughly twice as much here than it does in US.)

I already own a 250GB external HDD, so I wanted to attach it to AEBS for either file sharing or, hopefully, wireless Time Machine backups.

(Too bad Apple officially said only three days later that they don't support Time Machine backups with AEBS. Meaning, if it works for you, you're lucky, but if it doesn't, you're on your own.)


My experience is that even when Time Machine is not involved, AEBS can't handle a USB drive at all. Just attaching the drive to the base station will cause it to come online much more slowly (needs several minutes after plugged in). Also, whenever I wanted to mount the drive through Finder on any of the Macs in the house and transfer a file to/from it, AEBS would become inaccessible in a minute or two, then spontaneously reboot. With no drive attached, it's stable as a rock.

Of course, you could claim that the drive is at fault. Now, the same drive works perfectly when attached to either my MacBook Pro, or to my iMac G5, both running Mac OS X 10.5.2. It was formatted and partitioned (single partition, GUID scheme, HFS+ journalled filesystem) on the iMac G5. As in, freshly reformatted and repartitioned once again in a desperate attempt to make it work with AEBS. Run Disk Utility's "Repair Disk" on it too, just in case.

Now, when the drive is attached to either Mac and shared from it, the other Mac can mount it wirelessly and even do Time Machine backups to it, without any problems. So, you know, the drive itself seems in order. But if I connect it to the AEBS, it kills the AEBS. AEBS firmware is also upgraded to latest, 7.3.1. I wanted to reduce the clutter on my desk by moving the HDD and its wires to the AEBS and am fairly frustrated with the inability to do so.

I repeat: the symptoms have nothing to do with Time Machine. With Time Machine off, and trying to access the drive over AEBS as a vanilla networked volume, AEBS dies in a minute or so. I suspect a firmware bug.

And then there's the speed.

My MacBook Pro is a first-gen Core Duo, meaning it can only use 802.11g, and can't be upgraded to use 802.11n. Still, 802.11g is 54 MBit/sec, right? Well, the fastest data transfer rate I could achieve moving data to the AEBS-attached HDD (before it crapped out) was a bit over 8 MBit/sec. On a distance of few feet between the devices. Not happy. I can understand various protocol overheads would chip off the bandwidth but I can't understand getting 14% of advertised bandwidth. Not even if it were half-duplex.

Okay, what about Ethernet access? I tried connecting over Ethernet to see whether the AEBS crashing problem is inherent to Wi-Fi, or is also present over Ethernet (result: it is present over Ethernet too). The MacBook Pro said the connection is 1000MBit/sec - fair enough, as both it and the AEBS are supposedly Gigabit Ethernet. Both devices use speed and duplex autoselect based on the cable actually plugged in. So, with 1000MBit/sec theoretical maximum speed, what effective throughput could I get? 72MBit/sec, tops. It ain't the HDD that's slow - it's a 7200RPM drive with USB 2.0, and when connected directly to the computer it is pretty much screaming fast.

And then there are application compatibility problems.

My wife Kriszti speaks quite a lot with her aunt over Skype, and with AEBS she experiences much more stalled audio/video over Skype. I actually subscribe to two broadband connections: a 4MBit cable and also a 1MBit ADSL as a backup. I moved the old router to the 1MBit ADSL (which previously wasn't available over wireless, being only a backup). When Kriszti had repeated Skype problems, I told her to switch to using the old wireless router, and lo and behold Skype works okay for her again, so her Mac tends to remain connected to the old router's wireless network (so our machines aren't on the same network, which is also a source of inconveniences). So: cable ISP with old router = Skype ok; cable ISP with AEBS = Skype not okay; ADSL ISP with old router = Skype okay. There's a pattern here, although in order to be able to claim with 100% certainity that it's a problem with AEBS, I'd also need to test Skype with AEBS connected to the ADSL line which I won't do now as it'd require too much uncabling/hauling/recabling.

So, we have a base station that crashes when you try to use an USB HDD with it, with disappointing speed figures, and apparently also causes problems for Skype traffic. The only really good point is that contrary to the old taiwanese no-name router I replaced, it has a better range and implements WPA/WPA2 in a manner that Windows laptops can also understand; both of these don't really mean anything to me, but it certainly makes the nice girl next door (who we give free Internet access in exchange for occasionally babysitting our kids) lot happier.

All in all, a disappointment.