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hybrid drives vs system ram

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I use Windows 7 64 with 12GB mem on my work computer (Nehalem) and OS X for all my personal computers. The Seagate Momentus XT seems to be easily the fastest notebook drive for the money. Even though it is so fast during most common tasks, it only has 4GB ram in it doing that trick.

This makes me wonder why my OS isn't able to just do the same thing. I look at my task manager in Windows and basically no matter what I do it just never wants to use more than around 4GB of RAM. I'm talking opening every app installed on my machine, opening ton of huge photos, opening huge CAD assemblies, etc all at once and it just won't seem to ever want to take advantage of more than 4GB. And when I close the apps the memory frees up again immediately rather than keeping the files around so Photoshop or whatever will load up faster next time around.

Why doesn't my OS (maybe Mac does and I just haven't noticed since don't look at performance monitor nearly as much as on work computer since work computer I constantly need all the speed I can get) use the other 8GB of system ram it has to serve the same purpose (actually even faster) as the smaller amount of RAM built into the Momentus XT? I've heard about Windows prefetch but according to my task manager it sure must not be doing much. I definitely have 64-bit Windows not 32-bit.

Just curious thanks

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se the other 8GB of system ram it has to serve the same purpose (actually even faster)
Uh, Superfetch should be enabled... Windows 7 does so by default.

At least in Vista memory will show as used by superfetch, not sure about Windows 7 (if it shows it as free when in reality superfetch is using it as "cached", or if it shows as in use).

. The Seagate Momentus XT seems to be easily the fastest notebook drive for the money. Even though it is so fast during most common tasks, it only has 4GB ram in it doing that trick.
It's NOT DRAM, it's flash memory. Much slower, and for reads only. Not even close to the same thing, and I think your idea of "fast" is simply unused to actual truly fast drives like a nice X25-M or Sandforce SSD. :P

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Why doesn't my OS use the other 8GB of system ram it has to serve the same purpose (actually even faster) as the smaller amount of RAM built into the Momentus XT?

Simple answer: they do. It's called a file cache and it's been there since a looong time (probably Win 95 / 98 or earlier). Ths OS caches the files you recently touched in system RAM and releases this RAM if you need it otherwise. Mostly it works quite well and you don't notice anything (*), except that a program starts quicker the second time you open it. It's not instantaneous, though, as there's still CPU and possibly other I/O load. Vista added superfetch to the mix. It's different in that instead of waiting for you to open your favorite firefox (again) upon boot it tries to speculatively preload it, if the HDD is unused for some time.

And as to why you're not seeing this in task manager: by default it simply doesn't show this memory as being used. Otherwise there'd be not much point of showing the number at all: it would always be 99+% filled RAM irregardless of what you're using your machine for. I guess that would confuse people a little ;)

MrS

(*) Win 2k would try to cache large video files even if you just tranferred them over 10 MBit LAN. And since at some point they're not going to fit the RAM any more it starts to page your programs - anything not currently active. That was about the only time that file caching got into my way, since it made the machine completely unresponsive for no god reason. I think it was fixed in XP, though.

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What the hell does this topic have to do with Kaspersky?

I dislike Kaspersky with all my guts. It is the virus itself. It is so invasive. It even writes alternate data stream of files and you can't even get rid of it completely. It is for imbeciles only.

I never understood why people would bring their systems to a crawl with antivirus software. A firewall and common sense is all you need.

2 decades of no-anvirus user here. So you can shove your Kaspersky crap where the sun dont shine.

You should treat your computer in much the same way, using an antivirus program to bolt up all points of entry so that you will be protected from viruses, Trojans, spyware and other forms of malware. There are a huge number of security companies offering antivirus programs these days and some are better than others.I use Kaspersky: http://www.trustdownload.com/Antivirus-and-Spyware-Cleaners/Antivirus/Kaspersky-Internet-Security-7.0.html

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I know it is :)

I just wanted to give some crap to this Kaspersky virus with this occassion. I never got the chance to speak my mind towards it over the years :)

its spam. a mod needs to delete the post.

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I know it is :)

I just wanted to give some crap to this Kaspersky virus with this occassion. I never got the chance to speak my mind towards it over the years :)

Please don't reply to spammers, just report 'em. Keeps things more neat.

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Kaspersky might be intrusive, disruptive, and the most incompatible piece of software ever, but it's still far better than all the other crap we have the pleasure of dealing with around here, namely Norton, McAfee and AVG...

Back to the original post. Yes, Windows does use the extra RAM for (pre)caching like the flash memory on the Momentus XT does, though it can't do it in exactly the same way for one reason - RAM isn't persistent. You cant use RAM for speeding up system startup, since when you turn off the system anything cached in RAM is not. That's where hybrid hard drives make sense, especially on laptops that are necessarily turned on and off more frequently than desktops.

As for Windows' prefetch/superfetch, MrS correctly mentions that (read) cache does not show up in Task Manager's "Used" memory graph, though if you look at the performance tab under "Physical Memory" then "Cached" it shows you how much RAM is being used for this purpose. This is actually a partial subset of "Available" - the rest being made of "Free" and write-cache. Write cache does show up in the used memory graph of Task Manager.

You'd be best looking under Resource Monitor for a better graph though (Task Manager => Performance => Resource Monitor). The memory tab in there graphically shows you how much is used for cache (like the flash memory on the Momentus XT), write cache, programs, and how much is not used at all.

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