sig-alternate.cls generates too much space at page bottom

I am using the ACM tex template sig-alternate.cls downloaded from this page, Option 2: LaTeX2e - Tighter Alternate style.

This page provides the minimum working environment, including files in the following figure.

I downloaded all the files and compile them with the CTeX suite (WinEdt 6, MikteX 2.9), the generated output PDF file has very large space at each page bottom, which differs from the original PDF on that page. My own generated PDF file can be found here, and the PDF provided by the ACM website is here. You can compare them with each other.

I am wondering why the page bottom space is so large when I used sig-alternate.cls, and how can I reduce the space.

• CTeX claims to be able to handle Chinese. So it is not surprised that your pdf is generated in A4 while ACM provides a sample in US-letter. Read the wikibook for more layout. – Symbol 1 Jan 14 '15 at 8:59
• By the way, CTeX is a suite containing several solutions such as LaTeX+CJK or XeLaTeX+XeCJK. Next time you have some problems on CTeX you should specify which part of CTeX you are using, compiler, MWE, and so and so. – Symbol 1 Jan 14 '15 at 9:04
• @Symbol1 I see, I forget to check the format. Though I am using CTeX, I am not writing in Chinese. I just like this software suite 'cause it integrates many useful tools. – Bloodmoon Jan 14 '15 at 9:48
• The last link in the question is dead. – Schweinebacke Jun 28 '17 at 16:00
• @Schweinebacke Because ACM updated their latex template, the link for the old template is no longer available. – Bloodmoon Jun 28 '17 at 16:07

I had a similar problem, I increased the \topmargin in the sig-alternate.cls file from 4.5pc to 6.5pc and it leveled out the margins.
\topmargin 6.5pc                % Nominal distance from top of page to top of box containing running head.

• Maybe is would be better to look for a line with \topmargin 4.5pc and change it to, e.g., \topmargin 6.5pc … Nevertheless, if the problem is the page size (see the first comment to the questions), wouldn't it be better to change the page size instead of only to increase the top margin? – Schweinebacke Jun 28 '17 at 15:59