Microsoft has released more details of what SP1 will bring to Vista, but Microsoft has advised Vista systems may experience sluggishness as a result of the upgrade -- or little performance difference at all.
In a new detailed document, Microsoft promises efficiency improvements to the SP1-enhanced operating system. In a tacit admission that Vista has had some difficulties copying files, Microsoft promises to cut the time spent copying files on a single machine by a quarter, and the time taken to copy from one Service Pack 1 machine to another by half.
Microsoft also claims that SP1 will reduce the time Vista takes to read large images by 50 percent and address a problem which can cause a five-minute delay when booting ReadyDrive hard drives.
However, users will not see a performance increase straightaway -- in fact the opposite may occur. Microsoft warns that performance directly after install may be more sluggish than before: "The Windows Vista SP1 install process clears the user specific data that is used by Windows to optimise performance, which may make the system feel less responsive immediately after install. As the customer uses their SP1 PC, the system will be retrained over the course of a few hours or days and will return to the previous level of responsiveness," the document says.
Even Microsoft is playing SP1 down, with its director for Windows Client, Jeff Putt, concerned that people are expecting too much of it, especially as, he said, 90 percent of the improvements will have been already installed in updates.
"If you have done all the updates, I am not saying it will be trivial, but it will not be a big earth shattering thing that people expect it to be," he told ZDNet Australia.
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However, if Microsoft's SP1 document can be believed, only 20 to 25 percent of performance enhancements have been implemented through the updates, which could mean users downloading the update will see an increase in speed in file transfers and time to resume from hibernate.
Microsoft also confirmed in the document that it will address security vendors' concerns over restricted access to the Vista kernel, due to the Kernel Patch Protection feature in the operating system, by providing APIs for the 64-bit version of Vista.
"These APIs have been designed to help security and non-security ISVs [independent software vendors] develop software that extends the functionality of the Windows kernel on 64-bit systems in a documented and supported manner, and without disabling or weakening the protection offered by Kernel Patch Protection," Microsoft said in the document.
Both Symantec and McAfee voiced concerns last year that APIs were not available for the 64-bit version of Vista, claiming that restricted access to the kernel would hamper anti-malware development efforts.
The changes SP1 brings will not alter how enterprises see the operating system, according to IBRS advisor Joseph Sweeney. "There are no new features in there," he said, adding that enterprise IT managers are looking at the operating system and seeing no compelling reason to change from XP.
Speaking to ZDNet Australia earlier this year, Linux Australia president Jonathan Oxer said that many of the things about Vista which were groundbreaking such as the database based file system were pulled at the last moment because of time restrictions.
"There are a whole lot of things under the hood that they've had to take out to meet their shipping deadline," Oxer said, adding: "Vista looks like quite a different system, and it is quite a step up, but it doesn't have any of the really radical ground breaking underlying architectural changes that we were hoping for."
If these breakthroughs had been included, enterprises would have more of a compelling case to move to the operating system, according to IBRS's Sweeney.
Since SP1 does not contain these features, Sweeney's gut feeling is that it will not make much difference to enterprises. "It [SP1] probably gives Microsoft more than it gives the public," he said, only fixing things which should have been taken care of before the operating system was released, such as the speed and security issues.
Speed in programs such as Microsoft Office is not mentioned in the document, however, and in a test run by Devil Mountain Software, Vista with SP1 is twice as slow at completing tasks in Office than XP with SP3.
Users will be hoping some speed improvements do eventuate, as the service pack takes up a considerable amount of memory. Although SP1 has reduced in size from the 1GB quoted for test versions, the standalone download is still around half a GB at 450MB for the five language version and 550MB for the 36 language version.