slugs aren’t really slow

A recent email exchange with the friend who originally suggested that I take a look at the NSLU2 got me thinking about the machines we currently take for granted. In his email he outlined that he had consolidated a set of services previously run on a couple of old desktops (a Dell and a Shuttle) onto his slug – thereby making a big saving in power consumption. His slug now runs ssh, DNS, IMAP and SMTP mail and a couple of other services – a typical slug user’s profile. The phrase that got me thinking however, was his statement that “I’m quite amazed that it can do all this within 32MB memory”.

Now, not so long ago, 32 Meg of RAM was considered quite a lot. We seem to have become so used to desktop home machines equipped with multi GHz CPUs, 2 or 3 Gig of RAM and anywhere from 160 Gig to three quarters of a terabyte of disk that we are surprised that an apparently humble 266 MHz, 32 Mb RAM machine can do so much. But why? As recently as 10 years ago I was running a large public facing network on which the main DNS/mail and syslog server was a single processor Sun SPARC5 with only 32Mb of RAM. And I recall only 15 years ago (OK, so I’m old) running a network of ICL DRS 6000s providing full office system functions to over 1200 users. So I dug out the specs of the machines I was running at that time for comparison. It made interesting reading.

The smallest (in capacity terms) machine on my network 15 years ago was a DRS6000 L440 – which had a single 40 MHz CPU, 32 Mb of RAM and 2 x 660 Mb disks. That machine served 30 users. I also had a mixture of DRS6000s with older 25Mhz and 33MHz CPUs but with more RAM and disk store (typically 96 Mb and 4 x 660 Mb disks) each of those would support around a hundred users (the office application was memory not CPU dependent). The really interesting point is the pricing. I found a note with the following on it:

Item — Price (UKP)

DRS6000 L440 40MHz CPU — £15,000
(inc. 1 * 660 Mb disk)

64 Mb memory board — £11,000

32 Mb memory board — £6.550

SCSI daughter board — £800
(to support additional disks)

3 * 660 MB disks — £8,850

16 port asynch controller board — £1,500

ethernet LAN controller board — £2,660

external exabyte tape drive — £4,000

console and keyboard — £500

sundry cables — £200

hardware sub-total — £51,060

to which I had to add:

128 user licence for Unix 6, TCP and OSLAN — £11,000

(Thankfully, we had a site licence for the application software…)

So, for just over £62,000 I had a 40 MHz machine with 96Mb of RAM and 2.6 Gig of disk. Not bad.

Oh, I forgot VAT.