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zhuweirenqq

macrumors newbie
Original poster
Apr 9, 2015
4
0
Hello all,

I am a programmer, focusing on java, android, networks programming, and etc. Sometimes I have to open virtual machine, at most two. Do you think that it is necessary to buy a 16gb RAM mbp. I prefer to use the new mbp at least 4 years.

Thanks a lot!
 
If you are going to use VM's it is a must IMO... trust me, you should get 16GB now as you know you can't upgrade later...

It is not a MUST. It is certainly a nice to have. One or two VMs run fine in 8GB of RAM. Heck I've run them fine in 4GB of RAM.

Let's not confuse must have with nice to have. Must have means they won't run without. And that's simply not the case.
 
One VM: 8GB is plenty. Two VMs: Depends. Two Windows or Mac OS VMs with some software running will be tight (you'll have to assign about 3GB to each VM). One Windows/Mac OS and one compact Ubuntu Server (which can run e.g. with 512MB) will fit easily.
 
Do you think that it is necessary to buy a 16gb RAM mbp. I prefer to use the new mbp at least 4 years.

I'd go for 16GB for 'future proofing' if you can afford it, but don't sell a kidney - 8GB will probably do the job.

I'm doing web development on a 2011MBP (upgraded to a SSD) with 8GB using NetBeans, and often use a Win7 virtual machine to test on IE and run some Windows graphics software for icon design. 8GB seems to cope perfectly well.

What are you using at the moment? If you're on a Mac, run Activity Monitor while you're doing what you do. Ignore the 'free memory' (OS X uses spare memory for file caching and stuff) - in Mavericks and later it has a handy green/orange/red 'memory pressure' readout. On earlier versions look at the rate of 'Page ins' and 'Page outs' - if those are clocking up then the system is relying on disc storage to supplement RAM (see https://support.apple.com/en-gb/HT201538) - that's when things grind to a halt on a hard-drive based system (not so bad with an SSD).

I'd say you probably don't need more than 8GB of RAM unless you're dealing with bulky data (e.g. editing images at pro/print resolutions, working with big sound samples, HD/4K video editing). However, the fly in the ointment is the non-upgradability of rMBP RAM...
 
If you're doing programming and need VMs (I use them to host local servers that are identical in setup to my production machines) then I would say go for it. A windows machine and a Linux box plus the host OS X will chew through 8GB fairly quickly.
Plus as others have said, upgrading in the future is unlikely (plus I never heard anyone say they have TOO much RAM but a fair few saying they have too little....)
 
£160 for the upgrade is frankly obscene.

Additional 8GB from Apple or 24GB of the same spec SO-DIMM for a 2012 MBP from Crucial (and enough change for a large Pizza).
 
Really depends.

I personally could manage with 8gb, but 16gb is much nicer, especially with running parallels. It just seems "smoother" with 16gb. It could be psychological but it really does feel like it to me.
 
£160 for the upgrade is frankly obscene.

Additional 8GB from Apple or 24GB of the same spec SO-DIMM for a 2012 MBP from Crucial (and enough change for a large Pizza).

Agreed. And now they probably sell a LOT more memory upgrades because customers have no other choice anymore. $200 was a hard pill to swallow when I ordered my 13" rMBP with 16GB of RAM but I knew if I didn't do it right then and there, I'd be stuck with 8GB for the life of the machine. :p
 
Yep, just one of the drawbacks of having soldered chips.

Yep. I do also understand that soldering the chips was probably one of the ways they managed to get the new models so thin (a lot of super-slim Ultrabook PCs are like this, too), but still...they shouldn't be charging $200 for 8GB of additional RAM. That's just plain greedy. The difference in price between similarly spec'd DDR3-1833 SODIMM kits (8GB and 16GB) from Crucial is a whopping $62. A $100 upgrade price would be far more reasonable.
 
Get as much RAM as you need. For your use case, 8GB will be plenty - even down the road.

There are huge misconceptions* about system memory.
Many people think having more RAM means your machine will run faster, which is just plain wrong. Using 5GB of 8GB RAM has the same performance as using 5GB of 16GB.
Only when you use all of your RAM you will see performance decreasing. In normal usage it's extremely unlikely to reach 8GB. Even then, swapping out stuff on the 1GBs SSD is not the end of the world and will not bring your system to a crippling halt like a slow HDD might.

The only use cases where I can recommend shelling out $200 for 16 GB of RAM (which is a ripoff tbh) is heavy VM use (more than 1-2) or video editing.


*Also: OS X tries to keep as much stuff in the RAM as possible. If you see 8GB of 'used' memory, that does not mean you are out of system memory, but that it will replace the stuff you have not been using for a while (but it kept in memory anyway for faster possible restart). Also, OS X compresses memory content, increasing the effective system RAM.
 
Yep. I do also understand that soldering the chips was probably one of the ways they managed to get the new models so thin (a lot of super-slim Ultrabook PCs are like this, too), but still...they shouldn't be charging $200 for 8GB of additional RAM. That's just plain greedy. The difference in price between similarly spec'd DDR3-1833 SODIMM kits (8GB and 16GB) from Crucial is a whopping $62. A $100 upgrade price would be far more reasonable.

A $62 upgrade price would be even more reasonable. One might even say it would be fair.
 
I'd go for 16GB for 'future proofing' if you can afford it, but don't sell a kidney - 8GB will probably do the job.

I'm doing web development on a 2011MBP (upgraded to a SSD) with 8GB using NetBeans, and often use a Win7 virtual machine to test on IE and run some Windows graphics software for icon design. 8GB seems to cope perfectly well.

What are you using at the moment? If you're on a Mac, run Activity Monitor while you're doing what you do. Ignore the 'free memory' (OS X uses spare memory for file caching and stuff) - in Mavericks and later it has a handy green/orange/red 'memory pressure' readout. On earlier versions look at the rate of 'Page ins' and 'Page outs' - if those are clocking up then the system is relying on disc storage to supplement RAM (see https://support.apple.com/en-gb/HT201538) - that's when things grind to a halt on a hard-drive based system (not so bad with an SSD).

I'd say you probably don't need more than 8GB of RAM unless you're dealing with bulky data (e.g. editing images at pro/print resolutions, working with big sound samples, HD/4K video editing). However, the fly in the ointment is the non-upgradability of rMBP RAM...
Your comment is really useful! Thank you very much! I guess that I won't get jobs involving in editing vedios and photos in the future.

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If you're doing programming and need VMs (I use them to host local servers that are identical in setup to my production machines) then I would say go for it. A windows machine and a Linux box plus the host OS X will chew through 8GB fairly quickly.
Plus as others have said, upgrading in the future is unlikely (plus I never heard anyone say they have TOO much RAM but a fair few saying they have too little....)
Yes you are right. Upgrading RAM now seems more useful than upgrading on CPU (I mean the i7 option).

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Get as much RAM as you need. For your use case, 8GB will be plenty - even down the road.

There are huge misconceptions* about system memory.
Many people think having more RAM means your machine will run faster, which is just plain wrong. Using 5GB of 8GB RAM has the same performance as using 5GB of 16GB.
Only when you use all of your RAM you will see performance decreasing. In normal usage it's extremely unlikely to reach 8GB. Even then, swapping out stuff on the 1GBs SSD is not the end of the world and will not bring your system to a crippling halt like a slow HDD might.

The only use cases where I can recommend shelling out $200 for 16 GB of RAM (which is a ripoff tbh) is heavy VM use (more than 1-2) or video editing.


*Also: OS X tries to keep as much stuff in the RAM as possible. If you see 8GB of 'used' memory, that does not mean you are out of system memory, but that it will replace the stuff you have not been using for a while (but it kept in memory anyway for faster possible restart). Also, OS X compresses memory content, increasing the effective system RAM.
Yep, knowing how memories work is important for making desicion
 
I'll add my 2 cents here.

I have a Late 2013 iMac (not a Macbook but might be worth for the discussion) with 8GB RAM.

I have ran 5 vm's at the same time, one Windows 8, one RHEL, two NetApp's and one EMC VNX vm's.

You need to think that if you are using this for test purposes it doesn't really matter if some times it will get slower. Even with 32GB of RAM you will never get production environment performance to properly test it, you will need a REAL test environment for that.

So in my honest opinion, reinforcing here the word opinion, 200$ is not worth it. If you could upgrade it outside of Apple I would say why not, but for 200$...

Also on that note, more importantly is cpu because you do not mention what Macbook you want if a 13 or 15 inch.

Dual core cpu will be your limitation on the vm side of things, not the 8GB of RAM.
 

Thanks for sharing!

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I'll add my 2 cents here.

I have a Late 2013 iMac (not a Macbook but might be worth for the discussion) with 8GB RAM.

I have ran 5 vm's at the same time, one Windows 8, one RHEL, two NetApp's and one EMC VNX vm's.

You need to think that if you are using this for test purposes it doesn't really matter if some times it will get slower. Even with 32GB of RAM you will never get production environment performance to properly test it, you will need a REAL test environment for that.

So in my honest opinion, reinforcing here the word opinion, 200$ is not worth it. If you could upgrade it outside of Apple I would say why not, but for 200$...

Also on that note, more importantly is cpu because you do not mention what Macbook you want if a 13 or 15 inch.

Dual core cpu will be your limitation on the vm side of things, not the 8GB of RAM.
Very good reference to me
 
Get as much RAM as you need. For your use case, 8GB will be plenty - even down the road.

There are huge misconceptions* about system memory.
Many people think having more RAM means your machine will run faster, which is just plain wrong. Using 5GB of 8GB RAM has the same performance as using 5GB of 16GB.
Only when you use all of your RAM you will see performance decreasing. In normal usage it's extremely unlikely to reach 8GB. Even then, swapping out stuff on the 1GBs SSD is not the end of the world and will not bring your system to a crippling halt like a slow HDD might.

The only use cases where I can recommend shelling out $200 for 16 GB of RAM (which is a ripoff tbh) is heavy VM use (more than 1-2) or video editing.


*Also: OS X tries to keep as much stuff in the RAM as possible. If you see 8GB of 'used' memory, that does not mean you are out of system memory, but that it will replace the stuff you have not been using for a while (but it kept in memory anyway for faster possible restart). Also, OS X compresses memory content, increasing the effective system RAM.

No, just no. God no. Absolutely freaking no.

A normal MacBook Pro with Retina Display will start swapping data in RAM out to SSDs with only 8GB if you are running VMs. Even with SSDs, you are talking about an order of magnitude difference accessing something from disk (regardless of what it is) vs RAM.

And the OS starts kicking in its memory compression algorithms when it senses you are lacking in free RAM. And that's fine.. for 95% of what people do. Access an app for a while, leave other apps running in the background. But virtual machines completely screw up that pattern because the guest OS inside treats memory as literally *random access memory*. You'll notice if/when you run something like Parallels, it starts taking up larger swaths of "Wired" memory, memory that it has declared to the OS cannot be moved to disk. Similar with Photoshop, and that's because it is in use *right now*.

Because of this, anyone who ever says they currently use or may in the future run a VM, I discard the 8GB models completely. 16GB only. Yes, it costs more. But there is zero upgradability in these machines. Better safe than sorry.

Could you live on 8GB like these people are suggesting? Perhaps, performance of Apple's latest operating systems sadly gets worse over time, not better, on older hardware as they add new features.
 
No, just no. God no. Absolutely freaking no.

A normal MacBook Pro with Retina Display will start swapping data in RAM out to SSDs with only 8GB if you are running VMs. Even with SSDs, you are talking about an order of magnitude difference accessing something from disk (regardless of what it is) vs RAM.

And the OS starts kicking in its memory compression algorithms when it senses you are lacking in free RAM. And that's fine.. for 95% of what people do. Access an app for a while, leave other apps running in the background. But virtual machines completely screw up that pattern because the guest OS inside treats memory as literally *random access memory*. You'll notice if/when you run something like Parallels, it starts taking up larger swaths of "Wired" memory, memory that it has declared to the OS cannot be moved to disk. Similar with Photoshop, and that's because it is in use *right now*.

Because of this, anyone who ever says they currently use or may in the future run a VM, I discard the 8GB models completely. 16GB only. Yes, it costs more. But there is zero upgradability in these machines. Better safe than sorry.

Could you live on 8GB like these people are suggesting? Perhaps, performance of Apple's latest operating systems sadly gets worse over time, not better, on older hardware as they add new features.

My thoughts exactly... the poster you quoted doesn't think people 'understand how RAM works' :rolleyes: When having too little RAM slows down your work, at what point was that decision worth it?
 
Because of this, anyone who ever says they currently use or may in the future run a VM, I discard the 8GB models completely. 16GB only. Yes, it costs more. But there is zero upgradability in these machines. Better safe than sorry.
You cannot generalize it like that. I run a VM on my 8GB MBA all the time without any problems. The question is how much RAM you assign to the VM(s). E.g. Windows 8 with some office applications can easily run in a VM with 3GB, which will run perfectly fine on an 8GB OS X machine. You can also run several lightweight Linux VMs simultaneously on an 8GB machine.
 
You cannot generalize it like that. I run a VM on my 8GB MBA all the time without any problems. The question is how much RAM you assign to the VM(s). E.g. Windows 8 with some office applications can easily run in a VM with 3GB, which will run perfectly fine on an 8GB OS X machine. You can also run several lightweight Linux VMs on an 8GB machine.

But the OP said he runs 2 VMs... and what if in the future he needs to run 3 VMs, or 4? He could not do that terribly well with only 8GB of RAM.
 
But the OP said he runs 2 VMs... and what if in the future he needs to run 3 VMs, or 4? He could not do that terribly well with only 8GB of RAM.
Again, it depends on what kind of VMs we are talking about. But blanket statements like "discard 8GB models if you plan to run a VM" are simply not true. 8GB is plenty for the most common use case among Mac users (i.e. running a single Windows VM to be able to run some Windows software).
 
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