For a 2010 I'd try Yosemite or Mavericks.

Thank you popnwave much appreciated

My advise is to NEVER update past Yosemite on a 2010 mbp for use with serato.

there is no magic bullet in this case if you wanna keep using ssl and sdj. the crucial point is whether you wanna keep updating sdj or not:

- if you do, then you have to use the latest osx version that can run ssl. that way you can update sdj for as long as possible.
- if you don't care about further sdj updates then go back as far as possible. older osx versions are more resource friendly and have less crap included.

Thank r.a.c. Thank you I am going back to using ssl it's just more straight forward and way more stable sdj has got little bugs and glitches and it's not nice when you are a working dj so ssl is the way forward for me but I still want to keep sdj but I won't be updating it that much if that makes sense

sure that makes sense. and it's the same i do.
every once in a while i check the current sdj version just out of curiosity but ssl is what i actually use.

If it's a intel core 2 duo 2010 Mac it will run like shit if you use any new version of SDJ esp 1.9 the processors are long outdated.

Here's your first problem...You bought an old outdated 2010 Mac 3 months ago. You need to understand that SDJ is not like SSL it uses way more CPU and requires a strong laptop. The machine you have now is not going to cut it in the long run. If your CPU bar at the top right of SDJ is RED or anywhere near almost a full green bar that means your machines specs are struggling to run SDJ. I see this way too many times on the forum. Research the minimum system requirements before purchasing a laptop cause not any laptop will be able to run SDJ.

a core 2 machine is fine unless you go crazy with the effects. for "normal" use the current sdj version takes roughly 50% more than ssl (when using 4 decks) which is still a fair bit less than what one core of an average core 2 model can handle.

Could just be a defective Mac my old 2010 was an intel core 2 duo but it only shut down and had issues w/video but it ran incredibly hot too. Few of the 2010 models had bad graphics chips not saying that's his cause but Sierra uses quite a bit of CPU I wouldn't be running it on an old 2010. Regardless of all this an intel core 2 duo is not meant for SDJ 1.8 or above. The minimum system requirements are an "iprocessor" i3, i5 or i7.

there're two types of system requirements:
1. technical
2. everything else

the first one obviously is a must. if that's not met the software in question doesn't run at all. in any other case however it's actually not a requirement but a recommendation. one that can have many reasons. reasonable ones but also economical ones such as having a deal with the hardware company to boost sales or such ... you get the idea.
the point here is to look at such things with a healthy distance.

Well first my cpu bar stays at quarter it never goes in the red it will go up to half now and then not often tho. I had no choice to buy the 2010 MacBook Pro it was a good price and pc laptop mess ( battery was giving me trouble)up so I needed something for the weekend as dj every weekend. To be honest with I am going back to scratchlive just less complicated. My MacBook Pro it's self never runs hot no other issues and plus I don't download on it

And yes it is a duo 2 core but I have put a hybrid 1 tb hard drive in there and 8 mb of ram so boot up time is super quick

Doesn't matter the processor is what the problem is which is why you have no issues running it with Scratchlive cause it uses less CPU. SDJ is a completely different application with more features which require more CPU and to be quite honest it is a CPU hog. Usually using fx or other features on a intel core 2 duo machine will result in dropouts or glitches in SDJ...whatever R-A-C is talking is a bunch of nonsense the processor is what matter which in fact is the reason you're having issues I highly doubt a laptop with an iprocessor would not result in this behavior. You're using an old outdated 2010 laptop it's almost 9 yrs old.

May want to read this thread. The "minimum system requirements" require an iprocessor which isn't an intel core 2 duo. DJ's that are using these laptops on SDJ are really risking it.

serato.com

This is why am going back to scratchlive dj tecniq. And this is will be going back to Yosemite

It's a good idea I've heard of many issues with Serato and Sierra which is why I never updated. However I'm not sure Yosemite would be a solution with your 2010

The thing is users think a brand new OS X will work smoothly with older computer systems. This is really not the case though as newer software esp Sierra requires more CPU. Yosemite may be the solution though and you may have better results.

Eventually you will have to upgrade your laptop if you want to use the latest versions of SDJ and stick with current technology. With every release will require more CPU as they are adding more features. It's always best to get a 2012 Mac or above model as they will run SDJ very well. A 2011 would do a fine job as all these models have iprocessors. Some of the 2011 models had bad graphics boards which is why I suggest a 2012 or above model. I know how you feel and I'm actually with you as Scratchlive is still an overall stable system cause it doesn't require as much processing power as SDJ it will always be better in that aspect I feel it is also less buggy and 2x more reliable. A majority of working DJ's will agree that Scratchlive is still an overall better program. I don't think SDJ will ever live up to SSL in stability. In a way I'd rather have a stable system other than more features. Hopefully the development team of SDJ can get things together.

which makes the cpu the less likely cause. however, if you wanna be sure you can easily check that by just looking at the activity monitor.
ignore the first couple of seconds right after loading a track tho because there the cpu always spikes until the waveform has been built completely.