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The biggest bottleneck in today's mac pro?

S

smitha96

macrumors regular
Original poster
Jan 11, 2005
101
0
It seems to me that in my everyday use of my mac pro (I.e. Opening applications, web browsing with lots of tabs, playing music) the biggest bottleneck that I encounter is in the hard drive speed. Is this a possibility?

I recently did a raid 0 on two of my hard drives and noticed considerable improvement. So are the hard drives a major source of bottleneck in some situations?

Thanks,
Alex
 
The biggest bottleneck by far is software -- there isn't anything that will utilize the 8 cores to their fullest. It's something 10.6 Snow Leopard will help a great deal with.
 
"Bottleneck" has a different intonation on a Mac Pro when you consider just how powerful it is across the board.

Current HDDs can't begin to saturate the SATA bus in single-mode, which is why moving to 10KRPM or 15KRPM units or RAID 0 arrays improve performance.
 
aibo said:
The biggest bottleneck by far is software -- there isn't anything that will utilize the 8 cores to their fullest. It's something 10.6 Snow Leopard will help a great deal with.
Click to expand...

Graphics applications can utilize all 8 cores.

I use After Effects CS3 and I push my 3.2Ghz 8 Core with 10GB of RAM to the fullest, so much that the fans kick in when all cores are in use.
 
definitely the harddrive.

Imagine our current mac pro's with desktop SSD drives.. now that will make a huge difference.
 
SDAVE said:
Graphics applications can utilize all 8 cores.

I use After Effects CS3 and I push my 3.2Ghz 8 Core with 10GB of RAM to the fullest, so much that the fans kick in when all cores are in use.
Click to expand...

does the After Effects use all 8 cores though?
 
aibo said:
The biggest bottleneck by far is software -- there isn't anything that will utilize the 8 cores to their fullest. It's something 10.6 Snow Leopard will help a great deal with.
Click to expand...

Actually, 10.6 on it's own won't help that much. The program has to be written to take advantage of symmetrical multi-processing. I imagine their SMP work will become another core technology, like Core Imaging and Core Animation. When Core Animation became available in Tiger, it wasn't like every Mac program suddenly became animated.

Although, I do believe that they will leverage their SMP technology in the other Core technology groups, accelerating them.

Storage will continue to be the bottleneck until we get something like holographic storage or enough cheap RAM that the system barely hits the hard disk.
 
The biggest bottleneck on the current Mac Pro is the system bus between both processors and the RAM. Quite laughable given the processing power available.
 
The biggest bottleneck is the person behind the keyboard.

And after a few beers the lag is ridiculous.
 
Animalk said:
The biggest bottleneck on the current Mac Pro is the system bus between both processors and the RAM. Quite laughable given the processing power available.
Click to expand...

Very true, especially the RAM.

Although beer is a close second. After 8 beers, things do move more slowly. But they taste better. :)

Mmmmmmm..... Heineken....
 
Of course it depends on what you are doing but the HD's are the slowest part of the core system(not including the CD/DVD drive).

Does anyone have any specs. comparing the performance between stock SATA software RAID 0 with 4 drives and the Apple SAS RAID card in RAID 0 with 4 drives.
 
smitha96 said:
It seems to me that in my everyday use of my mac pro (I.e. Opening applications, web browsing with lots of tabs, playing music) the biggest bottleneck that I encounter is in the hard drive speed. Is this a possibility?

I recently did a raid 0 on two of my hard drives and noticed considerable improvement. So are the hard drives a major source of bottleneck in some situations?

Thanks,
Alex
Click to expand...


I'm sure you are already aware of this, however just in case and for anyone that doesn't know.

In RAID 0(striping) with 2 drives you double your chance of loosing all your data if one of the drives fail or gets an error. RAID 0 is good for speed but risk of total data lost goes up every time you add a disk to the array.
 
lostngone said:
I'm sure you are already aware of this, however just in case and for anyone that doesn't know.

In RAID 0(striping) with 2 drives you double your chance of loosing all your data if one of the drives fail or gets an error. RAID 0 is good for speed but risk of total data lost goes up every time you add a disk to the array.
Click to expand...

Not to mention that Data Recovery is next to impossible from these drives and very very tough and expensive!
 
lostngone said:
yes, it is redundant but you lose a lot of space doing that.
Click to expand...

RAID storage normally has higher latency than a single drive, but it has much greater bandwidth. So, if you are not doing anything that requires more than 90MB/s a single drive is best for performance reasons. Go to 10K RPM SATA if you want to improve on that further, or 15K RPM SAS if you want the best performance.

This was a discussion about bottlenecks in the system. Different people have different bottlenecks. Someone trying to do uncompressed video is limited more by bandwidth. Someone trying to service thousands of database transactions will be limited by latency.
 
I still believe that the hdd is way behind in terms of technology.

If you really think about it the hdd has been around so long and hasnt really changed and its considered ancient technology.

Once the SSD drives are available at the same price of the HDD, more people will realize they dont need a faster cpu to get the best upgrade when the hdd's finally catches up, even the powermac g5's will be freakishly fast.
 
jjahshik32 said:
I still believe that the hdd is way behind in terms of technology.

If you really think about it the hdd has been around so long and hasnt really changed and its considered ancient technology.

Once the SSD drives are available at the same price of the HDD, more people will realize they dont need a faster cpu to get the best upgrade when the hdd's finally catches up, even the powermac g5's will be freakishly fast.
Click to expand...

I think that when we start to approach 16 or 32 GBs of RAM as being standard, you will see the file system depending on RAM to compensate for the lack of storage performance.

Imagine Vista's ReadyBoost on steroids. The OS image will pretty much be one contiguous file that is burst read into RAM and then executed, eliminating the need to open and seek between multiple files.

The trickier part are the writes. For best performance you want to write into cache and let the cache write back to disk as fast as the storage allows. The application is only blocked as long as necessary to copy the data into cache. The cache writes back to disk in a background thread/process. Of course, once you fill your cache, your application blocks... but with umpteen gigabytes of cache, most applications will never fill the cache.

But what will the OS do if there is a system or power failure? You actually want that write to make it back to disk somehow. Today you can find external storage systems manage large caches using battery backup, giving the disks the extra few minutes needed to write that data to disk when the system fails.

Seeing this sort of logic built into every-day systems means a revolutionary change compared to today's technology... from the power supply (having built in battery backup)... to the disk controller being able to queue up gigabytes of I/O to operate without the need of the CPU.

All of this could happen today, but not in a cost-effective manner. The first obstacle is the adoption of 64 bit operating systems and the associated price of massive amounts of RAM.

By the way, I am speaking from experience... I actively develop for both the Mac and PC, shipping a product that does real time processing of gigabytes of data per second. We spend significant amounts of time every release constantly enhancing our technology to reduce the effect of system bottlenecks.
 
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