Unfortunately, there is no specific answer to that question. Asset Management Suite itself is generally not a very heavy performance-wise, however it does run on the same Symantec Management Server as the Symantec Management Platform and other solutions.
Since you mention 1000 managed computers, I presume you are not going to use only Asset Management but some other solutions as well - I have seen only a couple of servers running exclusively Asset Management. More often than not there is a number of solutions installed and used - Inventory, Software Management, Patch Management and Deployment solutions are the most common ones.
Why I am bringing that up - each solution you have installed and are using will introduce more data that server has to constantly gnaw though. There are a lot of factors that affect the performance of Symantec Management Server and all of these are not easy to estimate.
To try and sum it up - hardware requirements depend at least (but not only) on these factors:
- Number of managed endpoints (having a specific number for this, 1000, is a good place to start)
- Solutions that are installed
- Usage of solutions (number of software packages/policies, simultaneous asset management users etc)
- Configuration (Frequency of endpoints checking in, inventorying frequency etc)
Now, after spending probably too much space explaining why estimating the hardware requirements is difficult and not answering the question, the best place to start is IT Management Suite Planning guide. It is a rather long document, explaining how Symantec Management Server functions and what you should know when planning on deploying one.
Altiris™ IT Management Suite 7.1 SP1 from Symantec™ Planning and Implementation Guide
http://www.symantec.com/docs/DOC3464
Specifically, I would strongly recommend:
- Reading through at least Section 2, Chapter 5 - Performance and scalability recommendations for IT Management Suite (Page 115).
- If you just want to look at Symantec's recommendation on hardware specs, Recommended IT Management Suite 7.1 hardware and Tables 5-9 (Pages 124-126) will give you a guideline.