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I'm in the process of building a new system, but I'm concerned with my overall system speed being degraded by certain components. I'm curious to know of others' experience with such situations, and what common/potential bottlenecks I should be aware of.

Could a 7200RPM HD reduce the overall speed achievable with a high performance 6 core processor and high performance RAM, and if so how noticeable could the difference be? If I were to build a system using some budget components, might I as well purchase all budget components?

I don't want shopping advice, but if anyone could help me identify potential issues I might be looking at, that would be greatly appreciated.

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Your hard drive will ALWAYS be your slowest link in the chain. This will only be important if you will be reading and writing from disc a lot. If your applications will do most of their work in memory, it isn't as huge a concern. – MaQleod Nov 21 '10 at 0:01
@MaQleod; Thanks, I have come to that conclusion and increasing RAM should circumvent such potential read/write lag, but am curious of other possible culprits too. – Northborn Design Nov 21 '10 at 0:03
Basically, if you're going to spend the money on a 6 core processor because you want high performance, buy the fastest drive you can. When just running a few apps, you'll notice a bigger difference between a 7200 RPM drive and a 10k RPM drive than you will going from 4 to 6 cores. Also make sure you buy high quality cables for your HDDs too. – MaQleod Nov 21 '10 at 0:09
Its not just HDD RPM - its also transfer speed. Make sure you have SATA2, and the drives are jumpered so its active (some drives have a jumper fitted so that they run as SATA 1). Also, the speed of your RAM has a big effect - so not just amount of RAM but also speed. If you can manage it, use ECC RAM for the extra assurance. But be aware that this will severely limit the choice of processors and motherboards. You cant use ECC ram with desktop processors (i5/i7, etc). – quickly_now Nov 21 '10 at 1:00

This kind of question completely depends on what you're using your computer for.

Except in very simple use cases, performance is hard to predict. So what you need to do is benchmark the applications and data sets that matter to you.

However, there are very few use cases in which the hard disk is the limiting factor. For performance, you want to have as much RAM as possible, so that all the data you need is loaded from disk once. This way hard disk performance doesn't matter (if it did, no hard disk (or SSD) is fast enough anyway).

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Thanks Gilles; I understand there are no hard-and-fast answers to this sort of inquiry, but my example was quite specific to my situation. I'm considering 10K-RPM or SSD, as I'm running various resource-hog applications, such as the Adobe CS5 suite, and IDEs like VS 2010. I just don't want to end up in a situation where I acquire various high performance, high cost hardware components, only to have the overall operating speed jeopardized by a slow HDD or other possible culprits. Any suggestions to common pitfalls that some may experience when trying to build a balanced system? – Northborn Design Nov 21 '10 at 0:00
@TomcatExodus: For development, the hit-or-break factor will be having enough RAM so that your compilations don't hit the disk, therefore your disk performance won't matter much. For heavy video editing, no realistic amount of RAM will be enough, so you may well need faster disks (and a suitable RAID mode — possibly RAID10 — possibly with a true hardware controller). The biggest pitfall is not benchmarking. – Gilles Nov 21 '10 at 0:34

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