Internet Speeds Terrible after Mavericks Install

Could it be because your download resulted in your ISP bandlimiting you ? Or a lot of folks around you are downloading Mavericks ?

Do you have a non Mavericks machine that you can test with ?

All good here on an older MBP via Wi-Fi:

What device did you upgrade to Mavericks? Do you still the issue?

I'm getting 57/11 Mbps. Also, have a hardwired ethernet

connection to my router.

Are you connected via WiFi or ethernet?

I have the same problem in a MacBook Pro (Early 2011). Speed is extremely slow (30 KB/s max.) via WiFi. Never had this problem with Mountain Lion. My brother doesn't have this problem with his laptop (also a MBP early 2011), the only difference is that he update the OS and I made a clean installation.

Do you see the slowness with both wired and wireless or just wireless? Can you run speedtest again and find out your speeds. Wireless is a shared medium so sometimes there will be some slowness due to the contention

Just wireless. Now, magically, speed is OK. But there're more people with this issue: http://forums.macrumors.com/showthread.php?t=1600822

I have the same issue. Late 2009 iMac is unaffected, but late 2011 Macbook air is extremly slow. Both are on wifi, and both are at the same range from the wifi spot.

Same exact problem, 2011 Macbook Pro with Mavericks, 16 gigs RAM and over 100 gigs HD space left. An iPhone, iPad and Macbook Air (still running Lion) have expected speeds when comparing #s via speedtest.net but my download speed on the same wireless network is literally 1/6th to 1/10th of theirs (and very inconsistent one moment to the next) - sometimes slower than even its own upload speed. Ping and upload speeds don't seem to be affected. This is the only machine at this residence upgraded to Mavericks, and it is just terrible for a platform that insists on such reliance to the internet.

I did not have this issue prior to upgrading to Mavericks and did not notice it immediately after that (but don't generally test speeds until I suspect a problem). Have tried rebooting machine, starting in safe mode, repairing perms, testing speed while logged in as Guest, turned Airport off and on, renewed DHCP lease, switching IPv6 to local-link (there is no "disabled" option in Mavericks) then back to automatic, etc. Lack of speed does not appear to relate at all to how busy the network or internet connection is by others.

Potentially mitigating factors:

This is an upgrade of Mavericks over Mountain Lion (which was a fresh install on the current HD after the old one died). We used to have a network of several older Airport Expresses; now a single router from U-Verse covers the entire area. The wireless network is closed, 802.11g, 2.4GHz, WPA2 personal security and same network name as the now-unplugged Airport Expresses (which had been WPS). A time capsule is plugged into the router and visible but set to not broadcast its own network. An AppleTV is also on this network and works fine. The router does note 22 (and only 5 via ethernet) unique devices connected to the network with perhaps 2/3 of them active at any given time.

Others with similar issues in Mavericks:

https://discussions.apple.com/thread/5470945 (8 pages) - intermittent drops on 5 GHz, while just really slow (due to issue between Mavericks and DHCP?) on 2.4 GHz

https://discussions.apple.com/thread/5506422 (4 pages) - won't reconnect to network automatically on wake, "fixed" by either disabling bluetooth or disabling iClould keychain

https://discussions.apple.com/thread/5498637

Proactive Maintance. Servers like all computers need memory purged and software reset. The simple process of rolling restarts of servers on a montly basis would speed up the downloads of everyone. I pay for a 110 down/ 40 up and my downloads of my library after buying a new ALIENWARE are taking hours per movie. All they need to do is a server and network restart.

I don't think that's the issue, Questornach. *All* other devices on my network fall within an acceptable download speeds bracket - only my laptop, updated to Mavericks, was having inconsistent download speeds of 1/5 to 1/10 the speed of everything else on the same network.

After reading https://discussions.apple.com/thread/5478413?start=15 and https://supportforums.cisco.com/thread/2156790 I decided to log in to the router itself and change the security from "WPA-PSK (TKIP) and WPA2-PSK (AES)” (the default setting) to just "WPA2-PSK (AES)”. Presto! Immediately my speeds improved to match the other devices. Eight hours later, they are still good.

Yes, that is for your wifi though. I was using hardwired.