So you are starting a new blog and just like every new blogger you are damn sure that you are gonna hit 1 million posts quickly. The first question that pops up in your mind is – How many pages/posts can a WordPress handle? Will WordPress be able to handle millions of posts or pages without any impact on page load speed / performance?
And the answer is – Theoretically, the WordPress can hold the forte and won’t slow down even with infinite number of pages/posts. WordPress is a simple and very efficient CMS. The problem could actually lie with the hardware on which you have installed your WordPress blog. WordPress can hold unlimited number of posts/pages provided the hardware supports it with sufficient processing speed and memory allocation.
The other player is this is MySQL. MySQL is designed to handle tons of data. So it never slows down wordpress after just a million posts unless and until MySQL is mis-configured(or the sql queries are not optimized)
The typical hardware recommended for efficient wordpress based blog is :
for smaller/newer WordPress with hundreds of visitors monthly …. shared hosting
for medium sized WordPress with thousands of visitors monthly …. VPS hosting
for large sized WordPress with thousands of visitors daily …. dedicated hosting
So the conclusion is, WordPress is a awesome Content Management System(CMS) and there is no need to doubt it for performance. Just make sure that MySQL is properly configured and hardware components are in line with the WordPress traffic requirements.