Windows Server 2008

Performance

We tested network I/O performance using both emulated I/O and various traffic/assault tests and found Windows 2008 Server performance has improved – and especially improved when Vista is the client.

Microsoft's new client and server TCP/IP stacks, encompassing both tcpip.sys and the older Winsock API kit, have been updated. The network interaction stack, NDIS, has also been upgraded from Version 5.6 to 6.0. The TCP/IP stack contains native, rather than emulated IPv6 support. Choosing either IPv4 or IPv6 support is an interchangeable action, and management is identical.

The new stacks also have the ability to dynamically respond to communications latency in network connections as they possess the ability to dynamically change TCP packet window size, which allows a communication channel to be more efficiently stuffed with data.

SMB 2.0, unlike SMB 1, has performance enhancements that are designed to allow greater speed. One of these enhancements allows for larger buffer sizes when both reading and writing files. More open files can also be sustained at a single exercise like a file folder copy, or the number of files open-for-write concurrently.

In our testing we found that under light loads, the effects in terms of speed of tasks like copying folders, streaming media and loading complex Web pages aren't strongly demonstrated, but the effects under heavy loads, however, favours performance for Vista, strongly.

Depending on the mixture of I/O (but pronounced under streaming media and heavy file copying), Vista can be as much as 43 per cent faster than Windows XP SP2 in copying operations and 18 per cent faster in opening concurrent streams.

This also means that there's a two-class affinity for clients of Windows 2008 Server Editions – Vista and everyone else, including Windows XP SP2, MacOS (we used 10.4.10 and 10.5.2) or other SAMBA clients that use SAMBA 3.0.2+ connection methods. If you have a client with the new stack, you're more efficient, and, therefore faster under higher loads, but you're a second-class citizen if your stack isn't up to date.

Windows Vista supports and is shipped with both SMB 1.0 and SMB 2.0, whereas XP supports only SMB 1.0. Microsoft claims that Vista should be able to obtain better file/folder copy speeds over XP, especially in networks with higher latency. In our lab, higher latency (emulation over Ethernet 10Base-T) or low latency (same network subsegment with Gigabit Ethernet), Vista completed folder copies at least 35 per cent faster, and in one run of tests, 71 per cent faster than Windows XP SP2.

As SMB emulation for Apple's MacOS and most Linux clients are based on Samba, which is also based on SMBv1, these clients were tested and, as expected, showed no improvement in speed when connected to Windows 2008 Enterprise Edition over Windows 2003 Enterprise edition on the same hardware.

Windows Server 2008 also supports TCP/IP processing to be offloaded to supported network cards. In such a relationship, the TCP/IP Offloading Engine (TOE) card doesn't interrupt any of the CPUs to service TCP/IP traffic and protocol relationship requests, ostensibly speeding up network throughput.

When we swapped from a Broadcom Gigabit Ethernet network interface card to an Intel TOE Gigabit Ethernet NIC, the speed effects become highly demonstrable – even for clients that use older SMB and non-Windows TCP/IP communications stacks (such as Macs and Linux clients/servers).

This change cut CPU utilisation (as measured by Perfmon) during our TCP SYN distributed DoS assault test from 48 per cent to 18 per cent, and in our TCP connections test from 61 per cent at peak to 16 per cent at peak. While TOE cards have been around for several years, we haven't seen the stark differences in performance from them.

We also assaulted the network side of Windows 2008 and IIS7 with a simple test get/post test that emulates a large number of users with get/post requests via http for delivery of static pages.

We were able to increase the number of gets (using two independent Gigabit Ethernet connections concurrently) by 32 per cent on the same hardware with Windows 2008 Server over Windows Server 2003.

Increased Web management

We didn't run a full suite of IIS 7 performance tests as we found bugs in our test tools. But Microsoft has revamped its Web server management application – IIS Manager, removing past administrative obscurities and adding support for multiple site hosting.

Web server management can now be performed over HTTP, so that remote administration can be done from a browser, without opening administrative TCP/IP ports on the target server.

IT managers can also delegate IIS controls to local administrators or Web-development teams, if desired. It's also possible for administrators to 'surgically' lock specific files, rather than give blanket access to configuration files or static page configurations, an administrative boon.

And instead of installing all features by default (and having some of them required to be running even if they're never used), IIS 7 allows administrators to install only necessary modules (there are more than 40 of them). This reduces the attack profile of IIS 7 dramatically.

Web service and application performance and errors are now piped to the WMI, allowing rapid identification of errors, and the ability for monitoring applications to provide triggers (for example instant emails) when monitored items fall out of ranges (think Microsoft Systems Center-based and other monitoring applications).

In all, controls for IIS have been almost reborn.

The consolidation of Active Directory services into three distinct groupings – Active Directory Domain Services, AD Certificate Services, and Active Directory Federated Services - gives administrators the ability to use fewer Active Directory components and plug-ins to manage diverse network needs.

As an example, Microsoft AD Federated Services improves 'extranet' ties between organisations that can manage external system users in a highly definable way for use of files and application services among the organisations.

Terminal Services can now be encrypted with Transport Layer Security so that conversations can't be captured from network wires and re-assembled. Screen raster size can be huge (Windows Vista and XP only), so that remote desktop sessions no longer need to be scrolled through a viewer-like windows.

And Terminal Services can also present applications through http transports that look as though they were running on our desktops as native applications (we used Microsoft Office).

Terminal Services configuration is simpler, with more capacity to control printing, as well as the aforementioned encryption methods and raster size, overall.