Cube Build Performance in 8.4 transformer

[snadgir30]

Hi Gurus,

We are upgrading cubes from 7.4 to 8.4.

Test build in 8.4 enviornment takes more time compared to cube build time in 7.4.

Usage of below performance tuning parameters is increasing cube build time.
1.MaxTransactionNum - 800000
2.WorkFileSortBufferSize -9000000
3.WriteCacheSize -65536 MB

Cube build time in 8.4 approaches (even then 15-20 mins more) to 7.3 build time only when all of above the parameter values are kept default including WorkFileMaxSize =1500000000.
Can any one tell me what is the impact of these parameters on cube building performance?
and when to use it?

I have referred to cognos 8.4 Transformer documentation - Chapter 9 for this.
Transformer is installed on window server 2003.

Any help/pointers in this regard are highly appreciated.

Thanking you in advance.

Cheers
snadgir30

[lowis33]

Maybe it's normal ... look at this link from IBM

http://www-01.ibm.com/support/docview.wss?uid=swg21393727

[nmcdermaid]

Transformer 8 automatically applies a group by to your queries where it can.

It would be best to take a look at the logs between environments and identofy which components are taking longer. For example you may find that for every query the OPRN phase takes longer but the READ phase is shorter.

Or you may find something totally different. Compare and post back.