isitreal - 6:26 pm on Oct 2, 2004 (gmt 0)

Scarecrow, the light blinks on: the question of 64 bit vs 32 bit, made me think of something, nobody is talking about the physical hardware used to run google. Their old system was built on homemade Linux boxes, running I'm going to assume on a 32 bit architecture.

Your point on the overhead involved in going to even a 5 Byte system makes enough sense to explain why they have not gone to it yet.

However....

It is now extremely easy to build very reasonably priced 64 bit white box servers running Linux, running AMD 64 bit processors, for probably the same or less per box than google spent building their 32bit system to begin with. Linux has supported 64 bit processors for a while now, definitely long enough for the technology to have become mature enough to implement on a google type scale.

How many times to you think they need to read and write the docID during these few days? It's a huge number. Now add extra CPU cycles to every read and write. It's a massive performance hit.

With this in mind, let's assume that there will be no need to change calculations done per cycle if they move up to a full 64 bit system. I'm going to assume that it's this that google has been waiting for: a full rebuild of their server farm, an upgrade to a full 64 bit docID, doing this halfway, to just 5 Bytes, would have been silly, better to hold off, mislead and obfuscate, to keep this process under wraps until the IPO was done, then start work hardcore.