We have customised e-shop based on Magento 1.6.2.
Our hosting is VPS/VMS 8GB Ram, 4 threads, SATA.
We have tried Nexcess SIP 300, but still it was not enough.
The site is slow, based on Google analytics, the average page load is about 10 sec (especially slow are category browsing and searching). And backend is slow too - product adding, product changing, order changing and so.
We have approx. 3k unique visitors daily, 50+ orders.
Our hosts says that SSD discs are not the solution, because our shop has huge amount of DB requests.
We have applied some basic optimisation - GT Speed - CSS combining, compiler, GZip,..
but we have applied a lot of customisations which probably leads to mass DB requests and does not use cache correctly.
Long sessions, category - out of stock products at the end, intelligent generating of upsell,crosssell, search optimisation, promotional gift module…
We have tried free FPC modules but they there are unreliable or do not support specific cache invalidating.
Could you recommand me somebody to analyse the site and say what needs to be done?