The Seagate Momentus XT Hybrid outperforms any 7200rpm platter laptop drive out there.  Significantly.

 

To answer your question:

a.  The Seagate Momentus XT Hybrid will be slower than almost any SSD I can think of.. so keeping your OS on a SSD and anything else you can budget will always be your best bet.

b.  The Seagate Momentus XT Hybrid outperforms any 7200rpm platter laptop drive out there.  Significantly.

c.  The Seagate Momentus XT Hybrid can provide read speeds of 200mbps+ for items the memory manager puts in its SSD part.. so if you click on a folder in LR, and it’s then read into memory, pulling files is really quick.

d.  A Seagate Momentus XT Hybrid 500gb adds roughly $10 over the price of a 500gb 7200rpm HDD.  I’m not exaggerating when I say there is no good reason to use anything but an XT Hybrid in your laptops.. for $10 you’re getting a huge performance boost.

e.  Lightroom has different components which will benefit from faster storage.  I’ll list them in the order I think is most significant and then annotate under which conditions this is mostly true.

    1.  LR Cache:  If you have an SSD for your OS and you have the room, in a two drive system like  yours, put the cache on the SSD.  This speeds up all aspects of using LR.

    2.   LR Library and Index:  This is where your database, thumbnails, and previews are stored.  The faster the better.  On a desktop workstation I put these on their own fast mechanical HDD.  But my LR library/indexes are over 600gb.. so any SSD this large becomes price prohibitive.  For a laptop, if you offload your files to a desktop and keep it light, a Seagate Momentus XT Hybrid would be ideal.

    3.  LR working files:  These would be where you store the image files you’re actively working on.  I’m assuming a laptop is not your main image processing tool, that you later upload to a desktop workstation.  If not, then you might also archive your LR working files.  This would also greatly benefit from a hybrid drive.

 

hybrid2

 

With all that said.. a ‘fast’ SSD taking up just one bay, would handle all these chores better/faster than a slow SSD and a hybrid.  Hybrids are great for their cost, much better than straight mechanical HDD’s.  But SSD’s outperform them by several magnitudes.  If you can only budget $110 per drive, get Hybrids.  If you can budget for SSD’s you’ll be glad you did.  Currently the SSD’s to look at are the new Vertex 3, or the Intel 310.. both are new 25nm tech and very fast.

I run a (then fastest SSD available) Crucial C300 256gb SSD in my 2.4 pound i7 laptop .. and it’s surprising how it outperforms most desktops more than a year old.  IF I had a second bay, I’d run it the same way, but I’d add a Seagate Momentus XT Hybrid to hold my work files, music, etc.  But I use my laptops not as a primary tool, but as a field expedient tool.. a tool to view, display, and process while on the road.

 

I run a (then fastest SSD available) Crucial C300 256gb SSD in my 2.4 pound i7 laptop .. and it’s surprising how it outperforms most desktops more than a year old.  IF I had a second bay, I’d run it the same way, but I’d add a Seagate Momentus XT Hybrid to hold my work files, music, etc.  But I use my laptops not as a primary tool, but as a field expedient tool.. a tool to view, display, and process while on the road.

 

A lot of information?  You might be surprised to learn “how to optimize LR performance” via drives, more/faster RAM, CPU’s, etc.. is one of the hottest topics among professionals.  Lightroom is a great tool, so we naturally want it to run as fast as possible.  So countless photographers have tested/timed all the possible configurations.  The bottom line, is that everyone uses LR a bit differently, and this difference is use can make one drive config perform for you.. better than another.

Great question!  Sorry I couldn’t provide a shorter more definitive reply.

Steve