Being throttled because of cpu usage

Nicky Vermeersch

Active member
I've recently made the switch to equip my site only with Xenforo (and some Addons) instead of Xenforo + Wordpress to save on resources (and with wp being a cpu hog I thought it would vastly improve). The problem was that I experienced serious performance degradation and even cpu throttling and I just had to do something about it. The entire site was moved to Xenforo, and at the same time I upgraded my hosting at Bluehost from Shared Hosting to Pro Hosting (which is around 250 USD a year)

However instead of fixing the issue, the problem remained! I hooked up the site with CloudFlare's CDN services to minify CSS, JS and do all other sorts of performance saving tricks, as well as serving static content on CloudFlare's CDN servers instead of mine (which lead to some very efficient request saving and bandwith saving however). It even happens sometimes that CloudFlare detects my site as being offline, where I have to 'View the Live version'. When I asked Bluehost's support why this is happening, they replied that the problem lies within CloudFlare, and that I should perhaps disable CloudFlare alltogether to prevent those issues.

I also enabled phpfastcgi (though that only works on php 5.2 at Bluehost) to increase php performance, but that didn't seem to give any notable gain.

I've sent a request towards Bluehost's Support and received an answer among the lines that my website has too much static content that isn't cached by the user (the files he mentioned however weren't really static, as they are avatars of A service that offers avatars of players who are online in my game server) Though those ~12 marginally small files aren't cached by the client's browser, I don't see how this can increase the cpu to the point where I'm being throttled? :\

Personally I feel like I'm being sent around by their support, fixing non-issues while the actual problem lies somewhere else. They also said prior to my upgrade to Pro hosting that my site had too many visitors, and they convinced me to actually go for their more expensive Pro Hosting to fix all my worries, but in fact it has not, even though I took some serious steps in an attempt to increase performance :(

Throttle example #1
Throttle example #2
CloudFlare report #1

Does anyone have an idea what could be wrong?

Nicky Vermeersch

Active member
Basically they advertised this to me as:

From: Bluehost Support Team <>
To: <snipped>
Date: Thu, 25 Apr 2013 12:05:36 -0600
Hello <snipped>,

Throttling usually occurs when the server cannot handle the traffic or usage being used. Your domain appears to be quite popular and our standard shared servers are not optimized to be able to handle that amount of usage.

For accounts that need more resources to function correctly, we do suggest our Pro plan. Pro servers offers a substantial speed increase, due to the fact they only hold 10-15% as many customers as a standard servers.

Also included is a large list of our Professional services, such as:

+ Site Backup and Restore Pro ($12.99/year value).
+ Secure SSL ($49.99/year value).
+ 10 separate Postini Accounts ($1/domain, per year value).
+ Dedicated IP Address ($3.33/month value).
+ Domain Privacy ($11.99/year value).

Usage upgrades:

+ File Count: 300,000 (Increased from: 200,000).
+ MySQL Table Limit: 3,000 (Increased from: 1,000).
+ Email/hr Limit: 2,000/hr (Increased from: 750/hr).
+ Bandwidth Limit: 30Mb/s (Increased from: 15Mb/s).
+ And More!

You can research the Pro plan by going to: cPanel - Addons, or from the following link:

Let us know if we can answer any other questions you might have,

Thank you!

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When you have a new question or issue, please open a new support ticket.

A reverse ip lookup showed that getting their 'Pro Package' isn't as promised.

I used to have Shared Hosting at which hosts 726 domains.
Now I have Pro Hosting at which hosts 443 domains, which is only 39% less clients.
They claimed that moving to Pro Hosting would remove a lot of issues such as IO bottlenecks, more cpu time for me because I'd get throttled less, lower seek times etc

I'm noticing intermittent stalls when navigating, but I'm curious about the spec of the so-called "Pro Hosting" you're now on - what did they quote you when you moved up to the better package?

Also find out from your host if they have installed (or you can install) any PHP Opcode caching such as Xcache or APC?

Currently I don't have any php Opcode caching at all (i think) though I do have access to ssh and could attempt to install it APC through there?

edit: you can see the specs at

Nicky Vermeersch

Active member
Now I'm experiencing major outages and pageloads into 20+ seconds. I don't think I have any sort of caching installed, though my site isn't exactly that busy as well. Reports that I took tell me that the First Byte to Arrive takes between 10-20 seconds :\

Nicky Vermeersch

Active member
Some moderators told me that they notice slowdowns as well, I'm not really sure if its time related or even visitor related as it sometimes appear during peak hours and even off hours

edit: I also started to notice that while I am browsing a thread for example, that I don't see the comment box on the bottom. Instead I see the moderator ribbon even though I have nothing selected. When the page would finally be fully loaded, this moderator ribbon would disappear and I would be able to see the comment box. :eek:


Well-known member
I have bluehost for a tiny WP personal blogs and it is slow as heck all the time.....for years! The only reason I left it there is because I am lazy (I'll move it this year!)

You shouldn't have to do all those tricks given the relatively low traffic on your server. Personally, I think if you can get a low-end VPS or something similar in the same price might be better!


Well-known member
The server is overloaded (load 40 as I look on it).

I never noticed that when I first looked - I've just checked now: Load Averages 24.75 - 24.61 - 22.90

If that's the "norm" for the server you're on, then it's unlikely to be your site that is causing the high load, but you'll certainly suffer as a result.

I'd speak to your host and ask them to look again at the server and it's high load and see if they can do anything to optimise it.

If not, look for another host and get moved. (y)

Shaun :D


Well-known member
I'd speak to your host and ask them to look again at the server

If you have to tell your host that the server is overloaded its'definitely time to move to a better host:
  • Either he knows about the overload and doesnt care because he oversells heavily (this particular host has the word "unlimited" over all the place)
  • or he doesn't know and then he should be no host at all

Nicky Vermeersch

Active member
I never noticed that when I first looked - I've just checked now: Load Averages 24.75 - 24.61 - 22.90

If that's the "norm" for the server you're on, then it's unlikely to be your site that is causing the high load, but you'll certainly suffer as a result.

I'd speak to your host and ask them to look again at the server and it's high load and see if they can do anything to optimise it.

If not, look for another host and get moved. (y)

Shaun :D

Yeah I basically feel tricked because their support convinced me into buying 'More and better'. But in the end it's the exact same hardware (though less clients - but not as promised).
The host itself is Bluehost, and the package I am using is their 'Pro hosting', which costs me 24 USD a month. I could get a much more powerful VPS for that money :\

I currently enabled very aggressive caching on CloudFlare, it seems that the speed has been improved, though I'm not really sure if that is because of the aggressive caching.

I asked them if they could install or allow the usage of APC, but my question got avoided and I got this generated email that just seemed to check for keywords in my ticket.

Ernest L. Defoe

Well-known member
If you're managing this yourself, I would bet that you could run a 1G DigitalOcean VPS for $10 and get better results. I do that on a few of my sites and it my CF stats are more than yours.

PC me if you want more information about my setup.

You could do as SneakyDave suggested get a VPS from DigitalOcean and control everything yourself. I got a test setup on one of their VPS's just more or less learning how to manage a server and install stuff. I've managed to install Percona, varnish, and a few other things. Or you can step up to a better shared hosting solution as I see you said you pay $24 a month with Bluehost and try out xFHost. I use them for my main site and I don't have many issues with them at all.

Nicky Vermeersch

Active member
The best thing is their monitoring system at

According to them a permantent load of 30 to 40 is ok.

View attachment 47087

View attachment 47088

Only the Bluehost monitor only tells you that 'It's Ok' I'm not really sure what they are monitoring with it (is mySQL overloaded? IO limit reached? Allocated CPU time exceeded?) A while ago I logged in through SSH for a few hours and used top to see what my actual personal load average was, and it was very very low on average (sometimes peaks to 7% for a second due to php, but nothing consistent or high)


Well-known member
Unfortunately, that's how BlueHost operates, and they have for years. They are owned by a company called EIG (Endurance International Group). They are known for buying up good and successful hosts and running them completely into the ground. This Wikipedia article seems somewhat up-to-date as far as the hosts owned by EIG:

Remember that if you do go with a VPS, cPanel is not included, so if you are used to managing your hosting, emails, FTP accounts, databases, etc., through cPanel, that is going to be an extra cost ($10-15/mo. generally).