Multiple people, including myself have experienced a loss in frame rate since the patch went live.
Unfortunately a lot of these issues are simply a fact of life, WoW has changed for ever and will continue to change. Just because you played the game before on your 6 year old PC doesn't mean you can now. Changes have been made to the graphics engine, especially the lighting which can have a significant impact on frame rates and, without a fairly well powered PC you won't be raiding at an acceptable (30+) frame rate in high/ultra settings come MoP, keep in mind some older/less powerful graphics cards are also now unsupported (Intel Series 4 in particular).
Some of the issues being reported on the forums are obviously not normal, people seeing 5-10fps on new PCs, MAC overheating problems, the black texture issues etc and I'm hoping most of these will be hotfixed before MoP goes live... but before posting dxdiags and complaints regarding the game being broken try the below and see if any of these improve your situation. I'm sorry if most of these are obvious to people :-P
First, the basics:
INGAME SETTINGS
As system requirements have increased it may be worth turning some of these settings down to see if they make an impact:
MULTISAMPLING - at 1080P it can cause a frame rate impact on less-powerful hardware, I wouldn't say you needed more than 4x MSAA, even on my HD 7970 it drops fps a fair bit moving from 4x to 8x. Alternatively, if you have an NVIDIA card you can turn this option off all together (1x) and enable FXAA from the NVIDIA control panel for a less performance-hungry version of antialiasing.
SSAO - Screen Space Ambient Occlusion, adds a "soft shadowing" pixel shader to approximate depth using the z buffer. In basic english SSAO is what's responsible for the "black blur" around characters, buildings and objects ingame. Not always completely successful in WoW but still looks pretty good and may have an impact on lower-end hardware, play around with the setting and see if it improves frame rates. It doesn't really impact performance on my PC
VSYNC - I like vsync but the fluctuation in FPS when it's enabled can be a bit of a pain. If you have an nvidia card then enable "adaptive vsync" from your nvidia control panel for the best image/performance ratio. If you don't like VSYNC fps fluctuation but you also don't like screen tearing then try using the ingame maxfps sliders to cap your frame rate at 60 (or whatever the refresh rate of your monitor is) I suggest using Triple Buffering along with VSYNC, this stops the switch between 60fps to 30fps if your frame rate dips below 60. For adaptive vsync on AMD cards (and a host of other tweaks) I suggest you download and play around with RadeonPro Beta:
http://forums.guru3d.com/showthread.php?t=322031
SHADOWS - Continues to be the biggest FPS killer in wow, especially in busy areas/wide areas. Turn it down, the change from ultra to high is virtually unnoticeable and will improve frame rates by a fair margin.
LIQUID DETAIL - effectively renders everything twice when you're near water... no reason for it to be on ultra unless you're taking screenshots. Turn it to "high" for the best image/performance ratio
VIEW DISTANCE - Blizzard seem to increase the view distance with each expansion, what used to be "ultra" is likely "high" now (I could be wrong). As nice as the views are (and will be in MoP) there's really no reason to take the performance hit - play around and see what suits you but I'd would recommend "high" or lower... hovering max hight above Stormwind on "ultra" settings I see a difference between 55fps and 80fps when going to view distance "high"
REDUCE INPUT LAG - An interesting setting because it doesn't actually describe how it works. Some people have said it's a setting for those on low-powered PCs whose hardware can't keep up with mouse input. I've found it to be the opposite. When your Graphics card renders a lot of frames it takes longer for mouse input to sync with onscreen frame rate and can cause a slight lag in mouse onscreen display, especially with Triple Buffering active. On ATI cards in particular the game can also experience strange stutters/judders unless this settings is enabled, regardless of whether VSYNC is turned on. If you find your mouse input lags significantly or you experience stuttery gameplay (especially in dx11 mode) then enable this setting and see if it helps you. It comes at a price, seeming to up the CPU load and may reduce frame rates slightly in CPU heavy areas. My theory is that this setting is effectively reducing the "render ahead" limit which stops the normal GPU process of rendering frames ahead of time and chosing one to display.
OTHER SETTINGS - Things like spell detail and ground clutter can have an impact in busy environments but I would personally rather reduce the draw distance and have the game looking prettier than have an epic draw distance and sparse landscape. Whatever looks good for you!
http://eu.battle.net/wow/en/forum/topic/5207772317?page=1#4
this page runs through some of the basic steps to attempt to fix issues, in particular:
"Try deleting the Battle.net folders, which can be found here:
[WINDOWS XP]
C:\Documents and Settings\All Users\Application Data\Battle.net
[WINDOWS VISTA/7]
C:\ProgramData\Battle.net
Note you will need to enable hidden files and folders on your system in order to see the Program Data folder."
If you had addons installed pre-patch then it's a possibility that one of them could be causing compatibility issues with 5.0.4!
1.) update all addons via curse and try again
2.) if there's no improvement delete your CACHE folder, move the WTF and INTERFACE folders to the desktop. Boot the launcher and, from the top left dropdown menu go into game preferences and click the big, red "restore defaults" button to clear the game settings. Reboot your pc, log back into wow and see if this has made an improvement. If it has then it's your choice whether to attempt moving the addons back into the game's directory (choose the merge + don't replace files option) or, to minimise the possibility of ending up with issues again you could just start installing addons from scratch.
3.) If this hasn't helped at all then you can attempt the below:
CHANGE WOW CORE AFFINITY
WoW will check on startup to see how many cores your CPU has, 2, 4 or 8 (virtual) cores in the case of a Hyperthreaded i7. WoW will then dynamically pick 3 of these cores to use. WoW will generally use Core 0 (the first core, confusing!) along with 2 other cores to process sound, addons etc. You can specify which CPU cores WoW should use by adding the below settings to the config.wtf file within the WTF folder. This can be helpful in the case of hyperthreaded CPUs because if WoW decides to use core 0 and 1 then parts of these overlap due to hyperthreading, additionally WoW usually tries to use core 0 which Windows will also be using for system processes. Since 4.2 WoW "should" use all cores dynamically but altering this setting yourself can improve FPS/loading times - if you see no difference simply take the line out of the config.wtf file and you're back to default.
play around with these settings by adding SET processAffinityMask "XX" within your config.wtf.
Intel:
i7 Quad core with HT - 84 or 252 (252 uses hyperthreading but keeps core 0 free, 84 for use of 3 physical cores)
i5/i7 Quad core which does not have HT - 14
i5 Dual core with HT - 5 (note - wow will default run over both available processors in dual core systems - no gain may be experienced)
Dual core with HT - 5 (note - wow will default run over both available processors in dual core systems - no gain may be experienced)
Dual core without HT - 3 (note - wow will default run over both available processors in dual core systems - no gain may be experienced)
I7 - Hex core (6 logical / 6 virtual) - 1344
AMD:
AMD tri core - 7
AMD quad core ( Phenom series ) - 14
AMD hex core - 56
UPDATE DRIVERS
AMD DRIVERS - Make sure to also install the CAP application profiles - NOTE, ON MY 7970 GOING FROM 12.7BETA TO 12.8 LOWERS MY FPS.
http://support.amd.com/us/gpudownload/Pages/index.aspx
NVIDIA DRIVERS
http://www.nvidia.co.uk/Download/index.aspx?lang=en-uk
When installing NVIDIA drivers make sure to click the "clean install" button under advanced installation.
CLEAN INSTALLING DRIVERS
In the past both NVIDIA and AMD/ATI had a habit of leaving old parts of drivers lying around once you had uninstalled them, although they have both made improvements when it comes to drivers there's still no harm in doing a clean install to minimise the possibility of driver conflicts... Download and install DriverFusion from the link below before starting these steps. Uninstall your AMD/NVIDIA driver from windows then boot directly into safe mode. From your device manager right click on the graphics card listed under display devices (will likely be a "VGA Adapter" now that the driver is uninstalled) and clicking uninstall + remove drivers. Once this is done (still in safe mode) run DriverFusion:
http://treexy.com/products/driver-fusion
Select the option to remove the drivers for the card you're using, go back into device manager and click "scan hardware for changes" it should pick up the VGA card again. Reboot back into windows and install your driver normally.
Update your chipset drivers, sound drivers, network drivers and BIOS - if nothing else it'll stop possible future incompatibilities with games, and an updated BIOS is always a good thing.
LAST RESORT
As a last resort just re-install wow... However, if this doesn't work...
MORE ADVANCED SHIZZLE
Right, now we're getting into the realms of the advanced! If none of the above has worked then it's more than likely just a problem with WoW and you can just give up now, accept your low FPS + wait for a patch that may (or may not) fix the problem... OR you could try and improve performance somewhat using the below tweaks. I take no responsibility for anyone screwing up their PC (unlikely, but everyone posts disclaimers these days)
DISABLE HYPERTHREADING
Do you have an i7 CPU? Use many hyperthreading-enabled programs? (CAD/Video editing etc?). If you have an i7 then Hyperthreading turns your 4 physical CPU cores into 8 virtual cores, while, in theory (and for benchmark tests like 3dmark11) this can improve CPU throughput when it comes to multitasking and hyperthreading enabled programs in reality most games are struggling to use 4 cores effectively, let alone 8... even BF3, which supposedly makes use of 8 cores does not run better with a hyperthreading enabled system. This is generally why gamers recommend the i5 processors over the i7s. If you navigate to the BIOS, under CPU management settings there will be an option to disable hyperthreading - turning it off gave me a boost in performance when it came to wow and I didn't notice any differences in other applications/Windows. Your CPU will run cooler too. If you do generally do a lot of CAD or video encoding then you may be better off leaving this setting on.
C1E AND SPEEDSTEP
Both of these options are enabled/disabled from within the BIOS. Intel processors use a BIOS enabled but software (windows) controlled technology called speedstep that can clock your CPU down when not in full use (to save power) by reducing the clock multiplier. While it should be smart enough to work flawlessly it can also cause some FPS dips when alt+tabbing between screens or, in worst-case scenarios can fail completely and not clock up to full speed. By disabling speedstep you'll likely see slightly higher CPU temps when in idle mode but it shouldn't be drastic. You should also set your Windows power plan to "high performance"
C1E is a BIOS enabled and Hardware controlled (motherboard) feature that also dynamically manages CPU clock speeds and voltage to reduce power when the PC is idle... again this can be disabled within the BIOS.
It's worth downloading CPU-Z and/or realtemp to monitor CPU clock speed and temps.
OVERCLOCKING
I can't stress how CPU hungry WoW seems to be, you can never throw enough CPU power at it... if you feel confident you can check a guide online to get a few more mhz out of your CPU. In terms of graphics cards, especially when it comes to laptops I wouldn't recommend overclocking unless you're confident in temps and/or you need to fix a problem with graphics cards being stuck in idle/2d clocks. You can overclock directly from your AMD CCC or NVIDIA Control Panel (if you have system tools installed) or from a 3rd party app like MSI afterburner.
