[SunRescue] Solaris >2.5.1 on 4/600MP & 4/330 Memory Boards

[James Lockwood]

On Thu, 2 Sep 1999, Christopher Drelich wrote:

> Since we're on the topic of the Sparc 4/6XX, I'd thought I'd ask this
> question....Curently I will have 4 of the Cypress 40MHz CPUs, should I
> replace with 2 SM81s or 4 RossHypersparcs/200MHz/512Kb, or a third
> alternative?  Im looking to run Solaris 2.5.1 on this, so compatibility
> with Solaris 2.6 and 7 isn't neccessary.  Any help would be appreciated.

The best choice is the third alternative, which is to spend what you would
pay for 4 180MHz HyperSPARCs (the fastest you can use in a 4/600) and get
a low-end Ultra (used U1 or possibly U5 with a SCSI board).  The fast
Hypers are still much more expensive than the performance you get would
indicate, and the MBus quickly becomes a bottleneck even with 4 100MHz
HyperSPARCs.  180MHz with 512K e-cache would swamp it completely for most
things. 

For reference, specint92/specfp92 for individual CPU's in a 40MHz MBus
machine (some of which are extrapolated but should be close):

SM100:   22.1/ 23.4
SM41:    53.2/ 67.8
SM51:    65.2/ 83.0
SM61:    80.2/ 90.1
SM71:   101.6/ 98.7
SM81:   116.4/112.3
180MHz/512k Hyper:
        169.2/208.3

And some newer systems:

U1/170: 252  /351
U1/200: 289  /401
U5/270: 368  /410  (the 256k cache really hurts FP scores)
U5/333: 575  /656

You have a few choices: the cheapest one that would give you a big boost
would be to get a pair of SM61's.  This could probably be done for $300 if
you shop around, and would likely quadruple typical performance.  If you
have an early (non-FAS) SCSI controller on the mainboard and use SCSI disk
you should definately consider getting a faster SBus SCSI card.  5MB/sec
is a substantial bottleneck.

Next cheapest would be a pair of SM81's or a pair of 125MHz HyperSPARCs.
This could probably be done for $650-700 and would give you nearly 6x
performance of the dual SM100's.

I can't recommend going with quad HyperSPARCs, especially in a 40MHz MBus
machine.  The bus simply does not have enough bandwidth to keep things
flowing.  Dual SM81's work well by having more cache on each CPU, so they
give nearly double the performance of a single processor.  Quad Hypers
will lose more than 25% of their theoretical performance.

Used Ultra 1's can be found under $1k now if you look, and they will give
you more bang for the buck.  Used Ultra 5's or AXi-based systems will come
in closer to $2k but will offer more if you can handle the move to PCI.

I know that there is a certain masochistic pride in being able to keep a
4/600 running strong in this day and age, but they are simply not
cost-effective to expand past a certain point.

-James