Test: Impact of RAM on Windows 7 Boot Times (56k warning)

I accidently closed my browser, losing this post when it was almost finished mad , so I'll skip the introduction and jump right to the meat:

4 GB, Win7 x64: 54 seconds
3.5 GB, XP x32: 59 seconds
2 GB, Win7 x64: 52 seconds
1 GB, Win7 x64: 55 seconds
768 MB, Win7 x64: 80 seconds
512 MB, Win7 x64: 79 seconds
384 MB, Win7 x64: 101 seconds
256 MB, Win7 x64: 208 seconds

Windows 7 won't let me artificially set the memory below 256 MB, either in 64-bit or 32-bit. However, I have the 32-bit version running in a Sun VirtualBox virtual machine within XP. Which means I can artificially limit the virtual machine's memory below 256 MB. Since it's not native or 64-bit like the above tests I can't compare its startup times directly, but there's a section below on the road below 256 MB.

Testing procedure was to set the maximum memory amount in msconfig (except the 4 GB and 3.5 GB, where this was not necessary), reboot to have that amount running, open Task Manager to confirm correct amount, open Opera transfers tab to open restart script, close Opera, and to start the restart script. Thus each test is from shutting down with x MB of RAM, to rebooting with the same amount of RAM (not shutting down with 768 MB and rebooting with 512 MB). The XP test only slightly differed from this pattern, being rebooted after 35 minutes of light use. There was a slight margin of error from the reboot menu on restart.

Windows 7 was running with an approximately 4.2 GB pagefile (the default on my system); Windows XP Home x32 had no pagefile. Win7 was installed yesterday; Windows XP was installed about a month ago. Thus XP has many more programs installed, a few more drivers installed (memory card, webcam, fan - the ones I don't need right away), and a couple more programs running at startup. Neither had any security software (anti-virus, firewall, etc.) running, as the XP screenshot partially evidences.

Specs are Hitachi Travelstar 7K160 (7200 RPM, 160 GB, 16 MB cache), 4 GB Kingston DDR2 RAM at 667 MHz (PC-5300), Intel Core 2 Duo T7500 (2.2 GHz, 4 MB L2 cache, 800 MHz FSB).

Pictures/comments:

Win7, 4 GB



Quite fast, not a whole lot to be said here. As expected.

Win7, 2 GB



Actually a bit faster than 4 GB, probably just residual error. Not enough to make me decrease my memory .

Win7, 1 GB



A second slower than 4 GB, but I hit up instead of enter first on the boot meny and that added two keystrokes to the boot, probably accounting for most of the second. Windows was still perfectly fast after reboot. My guess is this will be the stated minimum requirement for Windows 7.

Win7, 768 MB



Reboot was a bit slower, but Windows was still snappy after the reboot. The amount of RAM used was still falling at this point, so it would certainly be possible to use Windows 7 pleasantly with 768 MB of RAM for light tasks.

Win7, 512 MB



Although reboot time was de facto the same as at 512 MB, performance was just noticeably slower. The reaction to clicks was sometimes just after the click, not instantaneous. 512 MB with Windows 7 is definitely tolerable, but is certainly not desirable.

Windows 7, 384 MB



Here the real slowdown began. 101 seconds is not bad for an OS that's been installed for a year or two, but is slow for a fresh install. The Start menu lagged a bit after being clicked, Paint lagged a bit upon being started - everything was somewhat slow. Upon shutdown, which was also noticeably slower, a notification appeared that some programs were not responding, although it disappeared before I could react. 384 MB clearly was not enough for Windows 7 to run in all its glory.

Windows 7, 256 MB



If 384 MB was swimming in heavy water, 256 MB was swimming in mercury. Three minutes and twenty-eight seconds is disturbingly slow for a fresh install, and the lag was bad after boot. Task Manager took a few seconds to start, and Paint took at least as long (not counting the increased Start Menu lag, either). When I hit Save in paint to save the screenshot, a "Not Responding" popped up on the Paint title bar before the Save dialog appeared. Shutdown was slower as well, and on the "Not Responding" dialog I was able to read that Paint and Task Manager were the offenders. You'd be better off running Windows 2000 (or XP or 98, for that matter) than Windows 7 with 256 MB of RAM simply because of the speed difference. 256 MB just isn't enough. I'd planned to try 192 MB as well, but by this point was tired of waiting for reboots - I had, after all, done each one twice, once to reset the max memory and once to test.

Windows XP, 3584 MB



Considering the older install and higher amount of software and drivers installed, as well as uptime, XP rebooted in essentially the same amount of time as Windows 7. Most of the difference was in the shutdown stage (especially "logging off"), which many years of XP usage have taught me tends to increase with how much you've been running. So if you're thinking of going to Windows 7 for quicker boot times, you'll have to count on the speed increase being after it's been installed a year or two. And only time will tell how much better Windows 7 really is at that. But considering that if it were an issue after a year or two you could reinstall XP nearly as easily (and more cheaply) than Windows 7, I'm going to suggest that boot times probably isn't a reason to upgrade.

The other huge difference, of course, is RAM usage. Windows 7 bottomed out at 562 MB of committed memory with 512 MB installed (discounting the two tests where it had no free memory at all), and happily went up to 743 MB of physical RAM used when given more space. XP, meanwhile, even with 3.5 GB to gobble up, fit in a svelte 186 MB. This is SP3, too! Even now, when it's been up an hour and has Opera, WMP, a couple Explorer windows, Calculator, and Command Prompt up, it's at 289 MB. So even giving Microsoft the benefit of the doubt, I don't think those of you with low-RAM, Vista-unfriendly PC's should be holding your breath for Windows 7.

Other Somewhat Disconnected Comments

*Thanks to illmatic8 for the reboot script!

*Curious observation: SuperFetch hasn't kicked in in any of the Windows 7 screenshots given the amount of free RAM. I'm not sure if this is because of the low uptime, the recent installation, or something else.

*Curious observation: The number of startup processes is nearly equal. I know three of the XP ones are from programs that I don't have in Win7 ( Taskix, which I highly recommend for its taskbar-reordering in pre-Win7 OS'es; Windows Messenger, which I don't even use, and I8Kfangui), so the 4 GB Win7 and 3.5 GB XP are actually running the exact same amount of unaccounted-for processes.

*Curious observation: Aero stayed on the whole time, even with 256 MB of RAM.

*If you like the XP background, I can send it to you - it's not copyrighted. Resolution is a shade north of 800x600 if I remember correctly, but it works well for at least 1280x800.

----------------------------------------------------------

New on Feb 15 - The Road Below 256 MB - With No Virtual Memory

I'd been using msconfig's boot settings to decrease the memory the whole time - much more practical than actually finding all these different sizes of memory DIMMs. But in Windows 7, you can't set the memory below 256 MB here. That you can set it that low at all perhaps is surprising - the stated minimum requirement will surely be at least 512 MB. So why is the limit at 256 MB? Well, Windows 7 really didn't fare that bad even at 256 MB - slow, to be sure, but it eventually did what you asked. Presumably, if you keep going below 256 MB, you'd notice some major problems.

It occured to me first to see how low an amount of memory could be used to install Windows 7 in the first place. I created a new virtual machine, set the memory to 128 MB, and tried to install Windows 7 32-bit. Right away, I get this message:



So much for that! I double the memory to 256 MB, which I already know works for running Windows 7, and try again. This time there's no problems creating the RAM disk. But when I tell it to install, there's trouble:



So it once more looks like 512 MB will be the stated minimum, even if it will run on less. But once you've got it installed, you can remove memory! And that's exactly what I decided to do.

I'd downloaded and installed the 32-bit version of Windows 7 so I could run it within XP. This installation was inside a Sun virtual machine, which has very easy settings for changing the nature of the virtual machine, including how much memory it has. If the virtual machine only has 200 MB of memory, Windows 7 will only see 200 MB, no matter what its minimum msconfig setting is. So I started testing with less than 256 MB! At first I went way south and halved it to 128 MB. I surfed the net for a couple minutes in the host XP, went back to Win7 in the VM, and the screen was mostly black with outlines of what looked like two profiles on a Welcome screen. No text was legible. Okay. I tried 192 MB. Better, but it didn't seem to shut down. So I really backed off. 248 MB came next.

With 248 MB, it actually booted in halfway decent time (this is 32-bit, remember, which may have helped). The desktop came up, and there was nothing particularly out of the ordinary. It saw the 248 MB of RAM, and gave me a nice warning:



What's that box with no text, you ask? Well, that's what I got when I tried to start Paint to paste a screenshot. Apparently there wasn't enough memory. So I had to take the screenshot from the XP host. After a restart I tried Paint again (with only Task Manager open) and it opened, and so did WordPad. But when I tried Notepad, it never appeared. And Windows Media Player, about 10 seconds after clicking its icon, gave me an error: "The instruction at [location] referenced memory at [location]. The memory could not be written. Click OK to terminate the program." It was only at this point that I realized that I didn't have any virtual memory for this machine. :wallbash: No wonder it was crashing rather than borrowing virtual memory!

I also noticed a graphical glitch on the Start menu with the Windows 7 Basic theme:



Not as big an issue as the two-programs-at-once limitation, but not the most pleasant thing every.

Windows 7 also did shut down with 248 MB of memory. But it took long enough to do anything noticeable after clicking "Shut down" that I didn't think it was going to. So it might have at 192 MB, too, if I had waited long enough.

So what did I learn from this experiment:

*It is possible to run Windows 7 with less than 256 MB of memory, physical and virtual.
*You should never run Windows 7 with less than 256 MB of memory, physical and virtual.
*If you get much less than 256 MB of memory, physical and virtual, very weird things start happening, but nothing gets corrupted. I'll post a screenshot here in a bit - or not. When I set the memory to 128 MB again and tried to start Windows, instead of glitchiness, I got our good acquantaince the Blue Screen of Death right after the "Starting Windows" screen with the fancy graphic. It took two tries, but I managed to snap a screenshot of it before it went away:



160 MB was enough to start, but it was pretty pitiful and looked like it was on its deathbed:



That's Task Manager - sad sight, isn't it? It eventually got that whole processes tab working, and the Applications and Services ones were there, but Performance never appeared. And the title bar also showed up with time. But a lot of time, as in several minutes! The poor beta fish background never did appear. Thus, I decided to abandon trying to keep testing Windows 7 with less than 256 MB of RAM - it's already worse than Starter Edition, so it's really not worth trying. Really though, I was impressed it worked at all once I realized I forgot to give it any virtual memory.

Still to come - what I thought I was doing here - testing Windows 7 with less than 256 MB of physical memory but with virtual memory!

Windows 7 with less than 256 MB of RAM - With Virtual Memory Edition

192 MB



Windows 7 32-bit in a Sun VM was surprisingly responsive with 192 MB of RAM. It was a lot better with the virtual memory than without. Response time was actually faster than 64-bit with 256 MB. There was no more "Not Responding" in Paint, and the lag wasn't horrendously long. It was roughly comparable to 64-bit with double the RAM (384 MB). Things did lag a bit, but really, it wasn't that bad. If you were running XP with 512 MB of RAM, you could actually run a Windows 7 32-bit VM.

128 MB

Another 64 MB off?

Nope, it's a BSOD. Apparently 128 MB isn't enough for Windows to start, regardless of how much memory you have. So I decide to halve until I find the minimum.

160 MB

I figured this one would probably work, since it started (kind of very slowly) without virtual memory at this figure. So I start it.



It still doesn't feel that slow. Still no lag in Paint's Save dialog, and shutdown is still faster than 64-bit with 256 MB. Internet Explorer takes awhile to start up after I accidently click on the "Find an anti-virus program" popup from the system tray, but it's still better than I expected.

144 MB

I have no idea whether this one will work before I try it, but...

It does! Responsiveness is similar to 160 MB.

136 MB

Just when I'm starting to think perhaps it just needs more than 128 MB...

Blue Screen of Death!

Nope. Apparently it needs more than 136 MB. I decide to try 140 MB.

140 MB

It works!

138 MB

Why bother? Well, I've already narrowed it down this much, so I might as well keep going until VirtualBox can be no more precise (it goes in 1 MB blocks). And... it works!

137 MB



Blimely! So 137 MB is the minimum memory requirement for Windows 7!

Now the question is, did it crash at 136 MB because Microsoft actually put a check in there for that, or does it really need exactly 137 MB of memory to run. Probably doesn't matter a whole lot since it won't install with less than 512 MB, but you might want to keep at extra 1 MB DIMM just in case.

And does it open more than two programs?



It sure does! I've got five open in that screenshot, not counting the Computer Info and Task Manager. They opened up slower than they would with tons of memory, but still faster than they would on a computer with a very old XP install and slow security software. And Opera actually runs well enough that I'm posting this update from the 137 MB Windows 7. I would test Youtube, but I don't have audio enabled on this VM right now. AJAX-heavy GMail seems a bit laggy - it takes a little while for the text to appear in the chat boxes - but it's not agonizingly slow. I'd advise a memory increase to anyone who has 137 MB, but I've got 10 tabs open here and I'm still typing!

So the conclusion: I'd wouldn't use Windows 7 64-bit with anything less than 384 MB of RAM at all - less than that and it's just not worth it. It will run with 256 MB, but you wouldn't want to write a Sticky Note with that little memory. 384 MB gives you enough to get basic tasks done, 512 MB the practical minimum, and by 1 GB you really don't notice a performance difference anywhere for basic tasks. Meanwhile, 32-bit can use as little as 137 MB of RAM, and isn't actually too terrible there. Sure, it ain't winning any speed contests with that little RAM, but I can use Windows 7 32-bit with 137 MB of RAM and feel like I was doing stuff, rather than always waiting for the computer to do stuff. Compared to 64-bit with 256 MB, that's quite good.

Now the question is, how would it do with 137 MB and a 600 MHz processor? Fortunately I can test that!

Addendum: Bit Rot

Bit rot is the term for the phenomenom that computers tend to get slower with time, even not considering the newer technology that is available. Generally this is attributed to the operating system becoming bogged down, something outside programs can be quite good at helping accomplish. 40 days after the initial tests, I looked at this again.

First I'll look at XP. I'd noticed some stages of startup took a bit longer than they had before. The restart time, 40 days after the initial test (which took place about 30 days after the XP install), was 72 seconds. That's 13 seconds longer than it initially was. Since then I'd added at least four programs that started with Windows, as well as many other programs. I followed jisaac's XP Tweak guide (although not applying every tweak), disabled unnecessary startup services/programs (except those I wanted to start with Windows for their functionality), and tested it again. This time, XP restarted in 52 seconds. This tied it with the fastest Windows 7 time, the 2 GB time. Closing all the system tray programs before restart brought it down to 51 seconds, but that took more than one second to do.

Then I went to Windows 7 and disabled startup services I knew to be unnecessary. I'm sure I didn't get it as optimized as XP, as there's a lot more services that I'm not familiar with, but I followed the tweak guide so far as there were no differences and disabled what I knew was safe to disable. At this point Windows 7 had been installed for about 30 days - I had had to reinstall it in late January. The restart time now was 57 seconds, with all 4 GB allowed (compared to 61 seconds midway through optimization - I didn't measure it before any optimization at all). Installed programs was a bit higher than in the January test, but that was the case for XP as well. I've also been using XP more than Windows 7 by a large margin - probably more than 3:1.

So looking at the times now, we have:

3.5 GB, 70 Days, Optimized, XP x32: 52 seconds
2 GB Fresh Install, Win7 x64: 52 seconds
4 GB, Fresh Install, Win7 x64: 54 seconds
4 GB, 30 Days, Optimized, Win7 x64: 57 seconds
3.5 GB, 30 Days, XP x32: 59 seconds
4 GB, 30 Days, Partially Optimized, Win7 x64: 61 seconds
3.5 GB, 70 Days, XP x32: 72 seconds

Conclude what you like - that Windows 7 suffers more bit rot, that XP suffers more bit rot unless you optimize it, or that Windows 7 is more optimized to begin with (which I think is true - I noticed at least one service that was enabled by default in XP and disabled by default in Win7). It may take more data points to be able to say anything definitive - had I not added any more programs to XP, I quite doubt it would have gotten up to 72 seconds to begin with. The same is probably true for Windows 7.

I should add that it is not safe to assume that this means XP is faster than Windows 7 in startup or will be faster after several months. It has a bit of an advantage on my computer in that it has the first partition on the hard disk. I gave the first 8% of XP's primary partition, and the next 12% to Windows 7 - when I partitioned, Windows 7 wasn't out, so giving XP the fastest partition only made sense. So XP's files actually load quicker from the disk by a small margin. I'm not sure what the exact difference in disk speed is - both are on the first 20% of the disk, however.

But if Windows 7 does indeed suffer more bit rot than XP, you probably would notice a difference a couple years down the road. Remember, however, this is just the beta, so by the time the final release comes, some of Windows 7's inefficiencies may well have been worked out.

I may add another data point or two to this section in a month or two. Mainly if I notice anything happening. I doubt I'll be able to test Windows 7 on the first 8% of the hard drive - unless I can just move all of XP's files to another partition, install and test Windows 7, delete that Win7 installation, move XP back, and still have the boot setup working just fine, I'm leaving XP there!

 

Wow, I wouldn't have been that motivated! It's nice to see that Win 7 runs "ok" with 512 MB of RAM and decently with 768. I guess I won't be shoving Win 7 onto my wheezing, designed for Win 98 SE, Pavilion desktop w/ 256 MB of RAM. It's still kicking around the house with XP now. I never expected to anyways

+ Rep

 

Nice job, I was wondering did you have the same set of programs/drivers installed in both win xp and win 7

 

No; XP has many more programs installed simply because I haven't had time to install most of my programs in Win7 yet. It also has a few more drivers - webcam, memory card, fan for instance - as I've been playing around with Win7 before setting up some of the lesser-used components out of curiosity. So XP does have a bit of a disadvantage there. Adding all the drivers to XP increased its boot time (not restart, just boot) from about 27 seconds to about 37 seconds when I installed it in December, so the difference in drivers probably is making up at least half the difference.

 

If they boot at about the same time then its good anyhow if you like the new stuff and the UI in Windows 7

 

That's nice to see Win 7 is working moderately well even with 1GB of RAM and still not too shabby at 512MB. Looks like a lot of under the hood improvements.

 

Great test, maybe I'm reading it wrong but it looks like with 384mb Win 7 is using 97% memory but with 256mb only using 92%?

 

Very nice, thanks for this.

 

I thought W7 was supposed to boot up much quicker than Vista?

 

Remember that those are not boot times, they are restart times.

Greg

 

Updated it a bit, with a new test: Running Win7 32-bit with less than 256 MB of memory and no virtual memory. I meant to test it with less than 256 MB and with virtual memory, but forgot I didn't have any virtual memory on my Win7 virtual machine, so I ended up testing it with no virtual memory and less than 256 MB of regular memory.

The good:

*It actually runs with (at least slightly) less than 256 MB of total memory.

The bad:

*It can only open up about two programs at once (even at 248 MB).

The ugly:

*Pretty much everything after you get significantly below 256 MB.

More details at the end of the first post.

The minimum I managed to get and be able to start Windows and type anything in Notepad was 160 MB.

I plan to test it with less than 256 MB and with virtual memory as well - that's what I thought I was doing at first! That'll be updated at some point, hopefully before St. Patrick's Day.

 

Where has he in his thread stated any vista boot/reboot times!? I can only see one from XP (except all from W7), and w7 is faster, you can't compare your own boot-times with his boot times as every system is different.


Nice thread though, fun to see someone had the time to test all that

 

thats such a good guide
i havent used Windows 7 yet and i dont think i will buy it im happy with Vista for now
but when i get my new laptop if Windows 7 is an option then i will get it

 

how was you able to run aero with 512 mb

 

My young lad is running it on an Inspiron 1521 with Aero and all.

 

but it aero requires at least 1 gb of memory

 

aero does need memory? on the gpu maybe, yes.. haven't seen that, but now i'm interested..

 

Vista Premium Ready, which is the "minimum" for Vista Home Premium, the lowest version that supports Aero, requires 1 GB. But that's just for the Vista Premium Ready label. Searching Microsoft's website, I found this page that, if you click on the "I thought my system can support Windows Aero..." question, says:

So apparently 512 MB is the minimum stated requirement from Microsoft for Vista.

But in Windows 7, as you can see from the above screenshots, you can run Aero with the minimum 256 MB of RAM with no problems whatsoever. True, Windows 7 runs a bit slow then, but I'm pretty sure it would without Aero, too. Graphically, it's fine at 256 MB.

Practical? Probably not. But 1 GB is an overstatement for Aero. Back in 2007 Lenovo was selling notebooks with 768 MB of RAM and Vista Home Premium - I'm sure they didn't intend them to be used without Aero.

I never turned Aero off, and it never turned itself off, either. Memory, it seems, is not the limiting factor on Aero.

I unfortunately cannot test GPU memory - I can't artificially limit it on my physical GPU (or if I can, I don't know how to), and the virtual machine GPU doesn't support Aero even if I give it the maximum 128 MB of VRAM.

I'll now test the VM 32-bit with less than 256 MB and with virtual memory. Seems to be running well with 256 MB and with virtual memory.

P.S. Does anyone know how long it takes for Reliability Meter to give you a score? Mine's probably going to be negative after all this. But it says it's too early (after install) to give a report right now - it's been about 10 days, though I haven't used the VM much other than this testing yet.

Update

I now have the absolute minimum RAM requirement for Windows 7: 137 MB! Says who you need 2 GB these days?

 

haha it sure runs well with 137MB

yes it was my though, except if the os has not enough resources to really handle it, aero doesn't rely on specific memory (it does need a bit as anything needs that runs). all it needs is a dx9 card that can render the screen (and for this, a minimal gpu memory region. but you would need that for anything you'd want to do at that res on the gpu so it never is a problem).