Re: Q: Is Xeon really fast?

Level 5 (as you can see below) has some extra overhead with write operation (for each write operation all disks has to be read, then SCSI device has to calculate XOR-s and store it). If your application is heavily modifying (inserting) tables, then it would be best to change RAID level, not to change processor. Or eventually change SCSI device to more efficient one.

From my experience it makes sense to put data devices on few RAID 0 disks (make backup often!) and log devices on RAID 1 (connected to another SCSI channel). Another RAID 1 for scheduled disk backup makes would be helpful as well. Using few SCSI channels (or even few devices) can improve performance.

--
Bronek Kozicki
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txm wrote in message <3665e1cc$0$214_at_nntp1.ba.best.com>...


>It's level 5. Does anybody know how it helps for Oracle or MS SQL?

>

>Thanks.

>

>txm

>

>nasof_at_hotmail.com wrote in message <743iae$l86$1_at_nnrp1.dejanews.com>...

>>If I am correct, I think you're right about no. 2 below.  This is because

 the


>>Xeon processors have an integrated L2 cache whereas the other PII's do

 not.


>>Until the Xeon, companies (like Compaq, Dell, etc..) where selling the

>>Pentium Pro's for servers because the had an integrated L2 cache which

 left


>>them faster than the higher MHz PII processors.

>>

>>As far as "will it help?"  My believe is the first way to tune an NT

 machine


>>is to through as much memory and CPU (speed & #'s) at it.  It certainly

 cant


>>hurt.

>>

>>For no. 3 below, RAID can help disk performance or it can hurt it.

 depending


>>upon what RAID level you choose.  For example RAID 0 will speed up your

 disk


>>usage, but it will provide no fault tolerance. RAID 5 is slow with writes,

 but


>>yields good performance for reads.  Do a web or newsgroup search

>>(www.dejanews.com is good) for RAID and research for yourself.

>>

>>-Frank

>>> Hi, all

>>>

>>> The company is thinking to buy quad 400 or 450 Xeon computer with RAID,

>>> which will cost $23,000, to run our software. Our software is a

 application


>>> server running on NT4, which heavily drives database. We support Oracle7

 and


>>> MS SQL6.5. When we run it on PII300 with a (relatively) good SCSI card

 and


>>> disks, it seems to be partially disk(database) and partially CPU

 intensive.


>>> It does not use huge memory.  If we try it on PII450(though we have

 not),
 I


>>> think it'll be more disk intensive.

>>>

>>> My question is: Does Xeon help this situation? In the other words, is it

>>> worth?

>>>

>>> My understanding of the differences between PII and Xeon are:

>>>

>>> 1. Xeon supports up to 4 multiprocessors.

>>> 2. Xeon's L2 cache is faster than PII.

>>> 3. I do not think RAID helps performance-wise.

>>>

>>> Does anybody have any good or bad experiences with Xeon? Personally,

 since


>>> it's more database intensive, I do not think PII and Xeon will have much

>>> differences even if we have quad Xeon. And Xeon costs much much more.

>>>

>>> Thank you in advance.

>>>

>>> txm

>>>

>>>

>>

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