custom cluster cabinets (was Re: 1U P4 Systems)

[Bari Ari]

W Bauske wrote:

> Bari Ari wrote:
> 
>> W Bauske wrote:
> 
> 
> I personally don't give a flip about 1U setups. I prefer 2U to allow
> breathing room for the components. However, your layout seems
> problematic. By that I mean physically mounting 8 2.5in drives, 8
> 1U power supplies or one exotic one with 8 connections, 8 LAN connections,
> and enough memory to keep the P4's occupied seems unlikely to fit into
> a "normal" 1U slot, say 17in by 28in. Are you assuming a different chassis
> length? 

I only figured for 16" x 16" x 1.25" for the enclosure and a another few 
inches in depth for fans and ducts to achieve the 800LFM since a P4 + 
chipset + memory + networking can easily be had in 40 sq. in. 16" x 16" 
gives you 512 sq. in. of total area for the two sides.

I figured using a 48VDC bus running between boards and regulating the 
+3V and +5V along with the usual Core voltages onboard much the same as 
is done in telecom apps.

Or, are you assuming something else about the layout I don't
> see? Using a single mainboard would, I think, require multiple power
> connections due to the P4's current draw. In case you haven't looked,
> a P4 uses 3 power connectors on it's M/B. These sorts of custom setups
> would probably preclude the use of GEnet and Myricom I would think.
> 
Depending on the chipset used 10/100 Ethernet would be included. GB 
Ethernet, Myrinet and SCI only add a few square inches each to the board 
space required. Increasing the enclosure size to 17" x 28" would give 
you plenty of space (952 sq. in) for these as well as a multi G-bit 
switch, plus you'd have much more surface area for cooling so the 
required LFM across the enclosure would drop or you could operate in a 
higher ambient temp. environment.

I really don't see P4's for dense clusters. ULV PIIIs and Athlon4 with 
SMP makes much more sense. IA-64 with SMP will probably come out ahead 
in MFOPLS per watt and $$. We're working with parts now that offer 160 
MFLOPS per watt vs. 20 MFLOPS per watt on the P4. Fixed point processors 
are down to 1 watt per 1000 Mips.

Bari