Date: Wed, 17 Apr 2002 13:46:51 -0400 (EDT)
From: <nick@snowman.net>
To: Baldur Norddahl <bbn-linux-kernel@clansoft.dk>
cc: Mike Dresser <mdresser_l@windsormachine.com>, linux-kernel@vger.kernel.org
Subject: Re: IDE/raid performance
In-Reply-To: <20020417173629.GA32736@dark.x.dtu.dk>
Message-ID: <Pine.LNX.4.21.0204171346260.3300-100000@ns>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org

Well what's your GFX card?  Anyone know the specs on a promise UltraDMA
133 or 100 card or the 760MPX chipset?
	Nick

On Wed, 17 Apr 2002, Baldur Norddahl wrote:

> Quoting nick@snowman.net (nick@snowman.net):
> > On Wed, 17 Apr 2002, Baldur Norddahl wrote:
> > > Quoting Mike Dresser (mdresser_l@windsormachine.com):
> > > > On Wed, 17 Apr 2002, Baldur Norddahl wrote:
> > > Motherboard: Tyan Tiger MPX S2466N
> > > Chipset: AMD 760MPX
> > > CPU: Dual Athlon MP 1800+ 1.53 GHz                                              
> > > Two Promise Technology UltraDMA133 TX2 controllers
> > > Two Promise Technology UltraDMA100 TX2 controllers
> > > Matrox G200 AGP video card.
> > > 1 GB registered DDR RAM
> > > > Also, with 12 hd's, dual cpu's, etc, what kind of power supply are you
> > > > using?
> > > It is a 350W powersupply. I wanted something bigger, but couldn't get it for
> > > sane prices. I can't rule out that it is overloaded of course. If it is, I
> > > haven't seen any other symptoms, the system is rock stable so far.
> > > Baldur
> > AMD recommends a minimum of 400watts for a dual athlon system
> > IIRC.  Ignoreing that the startup current on an IBM 5400rpm IDE disk seems
> > to be about 25-30watts.  Each 1800+ MP puts out 66w of heat, meaning it
> > uses more than 66w (I couldn't find the power useage stats) for a total of
> > 132 watts, so on boot ignoreing everything but the disks and the chips
> > you've got 12x25w (for the disks) + 2x66w (for the procs) or about
> > 432watts.  This will go down alot after all your disks spin up, but I'm
> > amazed your system boots.  Morale of this message:  Don't be a dipshit and
> > put 12 IDE disks on a single power supply.
> > 	Nick
> > 
> 
> I checked and it is actually a 400W powersupply. Sorry about that.
> 
> Actually the power usage for the 80 GB western digital disks are:
> 
> Spinup(peak) 17.0W
> Read/Write 8.0W
> Seek 14.0W
> 
> And for the 160 GB maxtor disks:
> 
> Spinup(peak) 23.7W
> Read/Write 4.8W
> Seek 5.2W
> 
> This adds up to 8*17.0+4*23.7 = 231W spinup and 8*14.0+4*5.2 = 132W during
> seek.
> 
> The Athlon MP 1800+ has the following stats:
> 
> Voltage: 1.75V
> Maximum thermal power: 66.0W
> Maximum Icc 37.7A
> Typical thermal power: 58.9W
> Typical Icc 33.7A
> 
> So the CPU maximum uses Vcc*Icc = 66.0W (wow they didn't lie about the
> thermal power).
> 
> It is not likely that both CPUs are burning 66W during the inital phases of
> boot where the disk do their spinup. Even then you might also be able to
> draw more current out of the powersupply than its rating for a short while.
> 
> For this discussion it is more interresting if it is enough during normal
> operations. Worst case we got 132W for the disks and 2*66W for the CPUs,
> which leaves 400W - 132 - 2*66 = 136WW for the motherboard, gfx, 4 promise
> controllers and the system disk. 
> 
> The recommended minimum powersupply for this motherboard is 300W.
> 
> Baldur
> 

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