Should I use Grav for a project with around 3500 pages and 25 languages?

After uploading 3300 pages in 3 languages(9900 in total), I noticed a big slow down in page load speed, search and admin panel.
I turned AdvancedPageCache plugin, and it speeds up these content pages, but search and admin panel are still very slow.

Grav has 2048MB memory limit on a dedicated server:
CPU: Intel Xeon E3-1270 - 3.4 GHz - 4 core(s)
RAM: 8GB - DDR3
Hard Drive(s): 1x 1TB (HDD SATA)

I searched here a bit and found that Grav is not the best choice for the 1000+ pages website.

As I plan to add 22 more languages, should I try to optimize the environment, add SDD and more memory, or it's better to look for other CMS or framework?

Any help would be much appreciated.

@Oleh, I haven't experimented with it yet, but the new FlexPages of Grav 1.7.0 should be able to handle tens of thousands of pages.

With Flex Pages we have tested Grav sites with over 50,000 pages!

See this blog about Grav 1.7. Scroll halfway until topic Flex Pages, 4th paragraph.