Windows Data Copy Limits Exposed, Sort Of

Redmond (WA) - Is there a limit how many files you can copy in one step? And if so, where is this limit? A post in the forums of a popular hardware site provides more clues where this limit may be and which hardware is affected.

We found this information earlier this week in a post on Ace’s Hardware where a user reported his findings. Hirschma writes that he was unable to copy large numbers of files under certain Windows/hardware environments and was confronted with an error 1450, causing an instability and requiring a system reboot. Depending on the Windows versions, he discovered varying limits: 760,000 in Windows XP 32-bit and about 2.7 million in Server 2003.

But there is a spicy twist to the story: Systems equipped with AMD Athlon Socket 940 (nForce3 chipset) and Socket 939 (Nvidia chipset) processors were passing the tests with flying colors, while machines using an Intel Core 2 Quad Q6600 or Intel Xeon 3070 processors failed at 760.000 files. A Server 2003R3, Xeon-based system failed at 2.72 million files.

Since hirschma’s 32-bit attempts on Intel failed, we felt there was enough reason to contact both Intel and Microsoft to find out whether this is a know issue, if it is considered to be an issue and whether a patch is in the works.

Intel told us that this problem can surface happen due to the Error 1450, which is described in a Microsoft Knowledgebase article. 32-bit platforms of both Intel and AMD apparently can be affected, and cause "backup not to complete successfully," according to the Microsoft post. The KB article, published on October 30, 2006 lists Windows Server 2003 and Windows 2000 as well as Windows NT4 as affected operating systems.

Confronted with this specific problem separating AMD from Intel systems, it took Microsoft some time to get back to us. In a brief statement, a spokesperson told us that "this is the first we’ve heard of this, and we are currently looking into why it is happening. We will follow up with additional context and any potential solutions as soon as we know more."

In the meantime, if you are running into an Error 1450 or expect to copy hundreds of thousands or even millions of files under Windows, Microsoft is providing a workaround through a Registry modification in its KB article.

Possible solutions for the problem have also been posted in teh Ace’s Hardware forum thread.