You should really work with someone who knows exalytics. Yes you should use a RAM disk to improve performance
look at the presentations from kscope Edward Roske did a session on exalytics as did a few others.
Since you're looking for relative improvement, what was your hardware spec before Exalytics? What kind of concurrency / load?
I'm going to bet that the OP works for an implementation partner - I doubt many end customers buy Exalytics speculatively without any pre-sale benchmarking / PoC.
I think of Exalytics as an incredibly broad river. Or very big pipe. That also happens to be pretty darn quick.
Or maybe a better analogy is (I am putting on my have-always-been-fascinated-by-warships hat): Exalytics is a really fast battleship (BB). There are destroyers (DDs) out there might be faster, but when you want to project power, BBs are the answer, not DDs. So clawing my way back to relevancy, Exalytics seems to provide fast performance and extremely large capacity. Other servers may offer roughly equivalent performance when it comes to completely isolated calculation tests, but then fall over when more than a few people use the box. <--I think TimG was alluding to this when he asked about concurrency.
Did you try this out using a RAM drive? (There are ways of mitigating Planning in RAM data.) What was your RAM disk performance vs. the physical disks? Do you have the flash pack? http://looksmarter.blogspot.com/2013/05/ExalyticsWithFlash.html
I am not believe in Exalytics because
Essbase it is old man - and can't do utilisation for all newest hardware.
-- Essbase CalcParallel - can't work correctly since 5 years from first implementation
-- Essbase Don't Really need in the RamDrive. in all performance test - it's getting only 20% vs SATA II drive.
Because Can't Calc more data block in single CPU mode.
My opinion it's simple
-If you need real decision for getting better performance
u have only one way - It's redesign application:
Use simplest Essbase calculation
NEVER use CREATENONMISSINGBLK and other
- create calculation from source slice
If u realy need big complex essbase calculation - use Essbase Custom Relation Calculation.