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View Full Version : Safari Javascript Back Navigation Lag Solved




jmxp69
Mar 22, 2013, 01:57 AM
I purchased a Mid 2012 15" rMBP about two weeks ago that came with 10.8.2. Pretty happy with everything except the Javascript reload delay when navigating back. I've been using OSX for a few years, and I know my way around pretty well. I tried everything to get rid of this annoying behavior.

Webkit Nightlies - Same issue
Chrome/Firefox/Opera/Camino - Scroll lag.
Single Process Windows - Same issue, just masked by absence of visible action
Reset Safari - No change
Disable Caches - No change
Extensions Off - No change
Adblock Disabled - No change
Extensions Removed - No change
SMC/PRAM Resets galore
CMD [ and ] - Same issue
Bottom Line: I'm not interested in Chrome or Firefox. Safari scrolls smoother and it's noticeable to me.
PS Watching the Safari error console shows lots of [error prone] JS on this site.

Network
Cable Speed - 20mb down and up.
DSL Speed - 7mb down, 1mb up.
LTE Tether - 20mb down, 3mb up.
Firewall - All content filtering disabled and tried through wifi on DSL (other side of firewall for guest use).
WiFi - 450mb to Airport Extreme 8ft away. Constantly get 300mb to NAS.
Tried Multiple DNS Forwarding Servers: 8.8.8.8, 8.8.4.4, 208.67.222.222, 208.67.220.220 and my hosted bind server.
Used adblocking host file--hundreds of lines of 127.0.0.1 for ad hosts

All the testing can be conducted right here on Macforums. With 10.8.3 go into any thread and swipe back. You should see a ~2-3 second blue status indicator delay in the URL bar. During this delay, I can't scroll up, down, back/forward, or click any links. This issue manifests itself on every website using Javascript (most) like Newegg, Amazon, Cars.com, Cnet, Engadget etc..

Disable Javascript and the issue vanishes along with key functionality of those sites. While I was tempted to go without Javascript or just toggle it on and off as-needed, I found this to be unacceptable for too many websites I use.

Time to get serious. I used Netboot from Mac Mini with OSX Server to boot a virgin 10.8 image. Low and behold--with no other software/configuration Safari works like a champ on MR/Amazon etc.. Javascript enabled--still see the blue bar on back navigation but it vanishes almost instantly.

At this point, it's not hardware, it's not retina, it's not the graphics card, it's not whether Javascript is on or off, it's not caching, it's something deep in the OS or Safari.

Boot back to locally installed 10.8.3--back nav lag is right back.

Did a Netinstall of 10.8.0 and voila, everything works the way it's supposed to. Took a dmg of this install for restore in the event I wanted to back out of the next step. Glad I did, it came in handy. Use App Store to upgrade to 10.8.3 with NO OTHER changes and my old back nav lag friend is back.

Most of my daily use with the laptop is on the web. I work very hard to ensure my network (dual WAN DSL/Cable), is up-to-snuff. After Netbooting 10.8.0 and seeing no issue, I eliminated the network and all the associated goodies: DNS, QoS, Content Filtering, Safari tweaks, from the equation.

I'm sticking with 10.8.0 for now and so far the only function I'm missing is iPhoto. The app store version wants 10.8.3 (or .2?) I'm happy with this because Safari feels supercharged compared to what I saw with .2 and .3.

So if you've been annoyed with this back nav lag issue this is one--admittedly unfortunate--option. Go back to 10.8.0. I might try .1, but I know .2 had the sleep/wake issue .3 cured.