If you need bigger iron, we also provide fully managed Drupal dedicated servers. Prices do vary based upon what's available at the time. Here is an example of a fully managed Drupal server we put into production for a client:

Base Server:
» CPU: 12 cores, 24 threads 8 cores, 16 threads
» RAM: 48GB 24GB
» Drive 1: 250GB SSD (or 1 TB SATA, not recommended for a Drupal server)
» Drive 2: None
» IPv4 Addresses: 5
» Bandwidth: 1 Gbps network connection w/ 30TB traffic 100mbit unmetered
» Operating System: Centos 6 64bit
» IPv6 Addresses: /64 Ipv6
» WHM/cPanel
» » $250 / month « «

Upgrades Available:
» RAM: 64GB + 30/m, 72GB +40/m, 128GB +120/m
» Drive 1: 500GB SSD +40/m, 2 TB SATA +$20/m
» Drive 2: 250GB SSD +$20/m, 500GB SSD +40/m, 1TB SATA HDD +15/m, ...., 3TB SATA HDD +35/m
» Drive 3: {same as Drive 2}
» Drive 4: {same as Drive 2}
» IPv4 Addresses: 13 +10/m (ARIN Justification may be Required)
» Bandwidth: 50TB @ 1Gbit port + 30/m, Unmetered 1Gbit port + 200/m
» More ...

This was true for the 24GB system, I'm no longer updating this section, but the example scales as bigger boxes are used. Depending on how resource intensive your Drupal site is, the above base server can handle approximately 50 to 90 concurrent requests, for a Drupal page, per second. With the RAM upgrade it would handle between 140 and 275 concurrent requests per second. Again depending on how robust your site is.

Like our Managed Drupal Hosting this includes quarterly Drupal updates and full server management.

These are individually created, so click Contact above, tell me what you want and your site's current statistics, and we'll get started.

Best Regards,

Michael
President
Internet Design Alliance

Footnotes:

- These take a minimum of 8 days to setup and includes me migrating one site to this server.
- The above is no longer available, but is a reasonable representative sample.

- Representative Server information (live data):

Summary:

Single site, ~450,000 pages per day, using ~5GB RAM, and ~15% of the CPUs.

Details:

AWStats
Day: 04 Mar 2015
Number of visits: 45,124
Pages: 489,231
Hits: 3,762,579
Bandwidth: 73.30 GB

# sar
Linux 2.6.32-504.8.1.el6.x86_64 	03/06/2015 	_x86_64_	(16 CPU)
12:00:01 AM     CPU     %user     %nice   %system   %iowait    %steal     %idle
Average:        all     10.10      0.08      2.35      0.03      0.00     87.44

# free -m
             total       used       free     shared    buffers     cached
Mem:         24019      22415       1604         31       4172      13505
-/+ buffers/cache:       4737      19282
Swap:         3999          0       3999

# uptime
 18:18:41 up 138 days, 16:00,  3 users,  load average: 2.51, 2.47, 2.59