I had the same issue as on Windows 8 with 64-bit. Apache is very slow, but when you press F5 many times, everything goes fine. In the end, I did a lot of work to solve this problem. Now it is fast.
To improve performance, try the following tasks:
Change apache listening port
Change the listening port from 80 to 8080 to avoid conflicts with programs such as Skype. Open the httpd.conf file and find the line starting with Listen (this is line 62). Change it as follows: Listen 127.0.0.1:8080

Change your power plan
Change your energy plan from Balanced to High Performance. You can do this in Control Panel\All Control Panel Items\Power Options

Disable IPv6
Credits for this particular task go to Jef , where he pointed it out in a blog post . On the Windows 8 desktop, simultaneously press Windows Key and R key

Type regedit in the Run dialog box and click OK

Use the registry editor to expand the registry tree and view:
\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\TCPIP6\Parameters

Right-click on Parameters , expand New and select DWORD (32-bit) Value

Enter DisabledComponents in the Name field

Double-click the new DisabledComponents value, enter ffffffff in the Value data dialog box and click OK

Confirm that the new registry value contains the required data.

Change your etc / hosts
If you use virtual hosts, do not add each virtual host to a new line. Instead, list them as follows. 127.0.0.1 site-a site-b site-c
I also added 127.0.0.1 127.0.0.1 since I heard that this somehow improves the search. (I canโt confirm it, but it wonโt stop putting it there)

Your hosts file is located in C:\Windows\System32\Drivers\etc
Check how many apache processes are running
In my case, I had two apache processes. Make sure that you have only one. You can verify this by pressing CTRL+ALT+DEL and press Task Manager

Disable Base Filter (BFE)
What I find works a bit is to disable the base filter. Since stopping or disabling the BFE service significantly reduces system security, you should only do this when necessary.
Go to Control Panel => Administrative Tools => Services => Basic Filtering Engine
<T411>
Stop the basic filtering mechanism by clicking Stop

Apache process priority increase
For your task manager and changing the Apache process priority from Normal to High by right-clicking โ Set Priority โ High 
Saving Apache Process
This is a bit ugly method, but it certainly works. It supports Apache and handles your requests faster. Paste your local web address into the iframe location and save it in an html file, run it and just leave it there until you finish.
<html> <head> <script> setTimeout(function(){ window.location.reload(1); }, 2000); </script> </head> <body> <iframe name="iframe" id="iframe" src="http://mywebsite:8080"></iframe> </body> </html>
Upgrade to Windows 7 Pro
As a user of Windows 8 Pro, you have the right to have the right to upgrade to Windows 7. Read more about this . For me, this was the only solution that really worked correctly.
Good luck