I think 1.7.8 or 1.8.3 is going to be your best bet.

its going to depend what hardware you want to run as well

Do a torture test befor using it on live situation.

Turn on wifi...
Set latency to 5ms (setting it to 1 won't let you go further)...
Run video if you use it...
Load and RUN All 4decks...
Set settings to 3 different effects mode - turn all 6 buttons left and right, tweak all 6 knobs left and right.
(If the version you're testing has PnT, turn it on too)

*if there's any features above that you will not use anyway, you can just leave them disabled.

The latest version I had my 2008 Macbook running fine is 1.8.2

Core2Duo support was dropped at SDJ 1.8 so not sure 1.8.2 or 1.8.3 are good suggestions.

Lol!

Because I tested the forward version that can still work on an old machine.

This is NOT my main laptop btw...
Just like my other 2009 Macbook, they're just backups of my 2 main ones.

I remember you have one of these too.
Just for fun, try to test 1.8.2 on yours and see if we get the same results.

I'll give at least 1.8.2 a shot. Would reverting back to 1.7.8 Be as simple as installing that update if things don't go well? I have my radio show tomorrow so I'll probably just run 1.7.8 for now to make sure and try the update tests on the weekend. FWIW I use an S9 at my radio station and I have a 61 at my house.

There were later versions that definitely change the registry and reverting back wouldn't fix this but I am almost certain 1.8.2 was OK. is there any real gain for you in using 1.8.2? If not I would seriously consider sticking with what you already know works. One thing is certain the CPU load has certainly increased as SDJ has progressed.

I suppose that's true. If it ain't broke don't fix it. Now I just gotta figure out a solution on a replacement machine since Apple screwed us all with the new USB-less MBPs.

I also have an old macbook pro :

MacBook Pro 13" Late 2009
Processor 2.53 GHz intel Core 2 Duo
Memory 4GB
Graphics NVIDIA GeForce 9400M 256MB

As you can see this is almost the same configuration than you except the cpu.

1.7.8 is perfect for this configuration.

I have also updated to 1.8.2 when i bought a numark nv (1.8.2 fix some issues) : both version works great and cpu usage is pretty the same.

As 1.7.8 and 1.8.2 have almost the same features and 1.7.8 is the last officialy supported version for core2duo i suggest to you to stay in 1.7.8.

I have try 1.9.x but this version is too cpu intensive and i have many audio dropout.

You can store/use multiple versions on the same laptop - just name them different names as you install...

Serato DJ 1.7
Serato DJ 1.8
Serato DJ 1.9.2

etc...

I use an older MacBook Pro and I have the latest installed for key detection and other off line library management but I play out in version 1.8.x

I think I have 7 versions Serato DJ 1.7.4 to 1.9.6 - need to read upgrade features and delete a few - lol

I forgot to mention that the computer has El Capitan installed on it...which was the reason I needed to upgrade in the first place...lol. So now the dilemma is 1.7.8 isn't compliant with El Capitan...but 1.8+ aren't core duo compliant...I might have to risk running 1.8 for tonight and then just figure it's time to cop a new machine sooner than later.

2008 mbp? Might as well use SSL to be extra safe.

I've found the fool proof workaround for at least my radio show tonight...now it's totally unorthodox...but it's going to work...I'm playing VINYL. lol...let's hope I'm not as rusty as I think I am. I'm gonna give all these suggestions a shot this weekend and I'll check back with the results. I'll just install a few versions and see which works best.

SSL 2.5 would work great. As for SDJ, maybe 1.7.8, but its still bloated and buggy in comparison. Anything newer is just worse.