ReadyBoost? ReadyRecycled.

Seit Windows Vista hat Microsoft eine Technik implementiert, die – laut Beschreibung den Speicher eines angesteckten USB Sticks als Speichererweiterung zu nutzen. Nur – wie neu ist das Ganze?

Wie ich das so sehe ist das was auf dem USB Stick passiert nichts anderes als eine Datei, die als Dateisystem eingebunden wird – Verschlüsselt – um dort Dinge auszulagern. Mit anderen Worten, ist es genau das, was man unter Linux mit dem erweitern einer Swap-Partition erreichen kann. Ähnlich wie es Microsoft mit dem Dateisystem in einer Datei macht, kann man so auf jedem beschreibbaren Dateisystem ansetzen, ohne seine Daten zu gefährden.

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12 thoughts on “ReadyBoost? ReadyRecycled.”

  • Well… I’m not sure who tool which concept up to now.

    Everybody feels like reinventing the wheel since vista – and they all are doing similar things at the GUI side. That leaves a bad taste in my mouth.

  • stackevil says:

    mich würden ja festplatten freuen die einen 512mb speed cache haben dann würde dieses beschisserne VISTA auch schnell laufen … wenn ich es den nutzen würde

  • I/O war schon immer ein Problem. Die CPU wartet drauf, dass die Platte, das CDROM, whatever – die Daten ankarrt.

    Würde man den Ansatz umdrehen und diese Vorgänge komplett asynchron ablaufen lassen, waere das einmal ein riesiger Tempovorteil, den man überall zu spüren bekommt.

  • stackevil says:

    wie sg sicher weiss gehen die perversionen am I/0 markt noch weiter .. wieso müssen festplatten ihre firmware von sich selbst booten … ein flash modul wär da besser angebracht … auch wenn der bereich nicht mehr zu schreiben ist ausser mit gewissen softwärchen .. trotzem irgend wo hirnfug

  • PMWarlord says:

    ReadyBoost was out way before Swapboost on Linux. Linux ripped off MS (not the first time…) Also, it’s not just a swapfile. The ReadyBoost cache is filled with memory pages that the system *predicts* will be needed. Swapfiles hold content that has been paged out due to memory pressure. The difference is that ReadyBoost will allow for better applaunch times or pagefault satisfaction for content that hasn’t yet been used in the session. Swapfiles cannot do that.

  • Ich denke nicht, dass die Discs das eigentliche Problem sind – eher das Handling im System, wie man damit umgeht. Die historischen Konzepte im Kernel…

  • I have to disagree with that PMWarlord, as linux keeps many things cached in memory as you have launched them. Prefetching apps into RAM and offloading them into swap is not a brand new thing. It’s used on linux systems since quite a while.

    Btw – multiple swap partitions/files are handled like a stripeset of some array, which increases speed too.

  • PMWarlord says:

    As you said: „…as you have launched them“

    ReadyBoost – because it ties into the SuperFetch predictive caching logic – is able to have pages ready to bring into RAM before you have launched them for that session. That means you always get the warm launch times vs. cold times initially then warm times on subsequent launches. It also means that it is considerably more robust to memory pressure and more likely to retain appropriate pages in the NVRAM cache vs. paging to disk. With SwapBoost or any other NVRAM swapfile arrangement, when sufficient pressure exists it will push good contents out of the small NVRAM cache and off to the slow disk. ReadyBoost and SuperFetch are resilient to that – the pages that are used most often will stay in the cache by virtue of their usage frequency whereas other, less oft used pages will be pushed to disk. Here’s the scenario: You’re working in IE when you decide to burn a DVD full of photos. Once that finishes you decide to play some WoW. After you’re done with WoW you go back to IE. With a conventional swapfile, the DVD burn memory pressure pushed out your IE pages, and then WoW pushed out those. Your NVRAM cache is full of photos and WoW bits. IE comes back slowly since it has to pagefault itself back in. With ReadyBoost/SuperFetcth the cache stays full of IE bits since that what is actually important to keep around. In that case, IE has nice warm pages that don’t have to wait on random I/Os to pagefault back in and is up again in no time. ReadyBoost is the shizzle. Swapboost is a pale imitator based on old-school compsci thinking.

  • So ReadyBoost is deciding on what applications are important to you. But what’s the benefit of always keeping IE in memory if you are playing a game except that it runs more slowly?

  • PMWarlord says:

    As long as the game has the memory it needs, IE being resident in memory has no impact on performance. But, that’s not really what’s happening with ReadyBoost. The game can have all the memory it wants – even pushing IE out of memory. By keeping the IE pages in the NVRAM cache it means that IE can come back up faster when the game is done being played. The key is random i/o times. When you’re done with your game and you switch back to IE, it has to pagefault any memory pages that were pushed out. 4KB random reads off of the HDD happens at like 12ms – meaning that if you page in 10MB of pages it takes 10sec+. Random i/o off of NVRAM happens at closer to 1ms, so that same 10MB comes in ~1sec. None of this affects the game perf since it’s the active foreground app and can snag all the memory it needs without being blocked on IE whatsoever.

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