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I have an older machine (athlon 1500+, 1.5Gb RAM) running XP on which I not currently running an on access virus scanner. I do scheduled scans with clamwin and malware bytes. I would like to find a cheap on access virus scanner that will not slow down this already painfully slow system.

I do software development and some of my compiles take over 15 minutes and are mostly disk IO bound. An modern update to what really slows windows down would give me enough information to make a wise choice.

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closed as not constructive by random Apr 23 '12 at 0:54

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I know a lot of people recommend NOD32, and it really is a great AV, but you should also consider Microsoft's (relatively) new Security Essentials. Not only is it free, but since they made the OS, they know all of the low-level API calls, and recent benchmarks place it's performance near or above NOD32 (this is not Windows Live OneCare as in the link you posted). It's also got a higher detection rate... – Breakthrough Jul 22 '11 at 13:21

12 Answers 12

up vote 12 down vote accepted

ESET's NOD32 is written largely in assembly language and is generally regarded as one of the faster, least resource intensive products in the category.

This may also help in your analysis:

(Though I'll be honest, I'm not sure I trust them... they seem to claim Norton is a good product... I've never seen Norton do anything but slow a system down).

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I love Nod32. When I had to research which AV we would use company-wide, I hands down recommended this after trying a million different products. You never even notice it running, uses almost no memory or pcu cycles. My only complaint is that it takes slightly longer at boot to load then some other, more bloated AV products. – tj111 Sep 9 '09 at 17:12
Nod32 may have a small footprint but I find it's protection to be lacking. I see systems running Nod32 come in often with malware. Now to be fair, I see systems come in with malware and just about every AV product out there. Just like most other AV products Nod32 doesn't do a great job of removing threats that are in the system already. For that I would say Malwarebytes or Avast's boot time scan. – Daddy Su Sep 10 '09 at 1:41
That's the thing - they all pretty much stink nowadays. Used to be the BAD programs caught 99% of what was out there... today, it's more like 80%. Maybe NOD32 gets 82% and Kaspersky gets 78% but at this point, they all pretty much stink. I've heard mixed reviews about Vipre - mostly in that it either works or they never see it reviewed/used to know if it works. – Multiverse IT Sep 10 '09 at 3:40

I use Avast at home on two single core processor machines - only a little bit higher spec than yours - and it doesn't seem to slow either machine down.

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Avast is extremely lightweight. I've been able to keep it running on a P3 with no real speed issue. – Tom Sep 9 '09 at 15:50
Lightweight, I use it too. However I see many reports and reviews that Avast is far from being the best in protection, at least in its free version. Though I never had problems with it, but I'm quite careful in general with what I open and do. – Gnoupi Sep 10 '09 at 9:52
I actually switched to Avast! ages ago, when McAfee and Norton refused to scan for trojan horses as they were not considered a virus by definition. So, maybe Avast! gives less protection nowadays (I am not on Windows anymore), but I give them lots of credits from my earlier experience. (The free edition may not be applicable when doing professional software development.) – Arjan Sep 10 '09 at 10:04

Try using Microsoft Security Essentials. I use it on my PC, and currently it's sitting in the background using just 1,116k (although it depends on your computer). It's relatively new, so there isn't as many benchmarks, but some I've read place it at the head of the pack for both detection rate and performance.

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I'm going to suggest something rather suprising...

running as a limited user hugely reduces your risk of getting a virus. While i do run an anti virus, and all my systems are behind a firewall/router (a wrt 54 g dd-wrt , though i'm considering supplimenting it with untangle), i haven't actually had any virus infections in years running limited user unless i need to.

I'd also look at windows steadystate as well - its not an AV, but a way to protect shared computers. Don't allow access to anything that dosen't need accessing- once again, lowering your threat signature.

I also tend to check any media that hasn't originated here in a VM before i use it, but i have a spare box, and a healthy amount of paranoia. What dosen't get in can't hurt me :)

I also take down systems every six months or so for a full image (call me paranoid ;p) and at this point i also run an offline virus scan before i do it.

Yes, none of this is an AV, but well, i haven't needed mine to do its job yet. What AV i use is an afterthought at this point. Panda cloud has the lowest memory usage of anything i've tested, but i'm not sure how it is in terms of actual detection in the wild.

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I also take down systems every six months or so for a full image (call me paranoid ;p) -- No, I'd call you someone who needs to switch. I have an hourly updated full image using "Time Machine" on my Mac, and I don't need to take anything down to get that... ;-) (And I don't run any virus scanner either, but that may change in the next years.) – Arjan Sep 10 '09 at 22:14
well, i run a mix of linux systems(i haven't found anything i'm really happy with for backups on it- though there's some promising rsync frontends -i currently do full system cp/tar backups ),and windows systems(macrium reflect or acronis personal for periodic backups - i'm thinking of getting backblaze for offsite backups at some point).Still, i tend to do imaging with clonezilla as well so that i have a consistant, bare metal restorable image for the 4 systems i have total control over, regardless of what OS. The full offline AV scan + offline backup isn't necessary - its paranoia :) – Journeyman Geek Sep 11 '09 at 0:32

Although personal opinions can help with this choice, I would advise to check out (independent comparatives of Anti-Virus software) they have been doing a lot of independent anti-virus comparisons for over a few years now. And it offers a good insight in the developments of the different products.

They run a "On-demand Comparative" to check the general performance for the engine when using signatures and the run "Retrospective/Proactive Test" to test how the anti-virus engine works detecting unknown viruses by their behavior. (The site won't like me to link to them directly, so browse to them yourself)

Only Kaspersky and ESET get the Advanced+ level in both test, and I know for experience that ESET is faster than Kaspersky.

Looking at the test, Kingsoft Antivirus scores the fastest scan rate but it does get the lowest rating on both tests.. So read the reports and make your choice :)

(I would go for ESET)

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and here's another popular one with a moderate footprint:

Avira AntiVir Personal - Free Antivirus

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Sandboxie - I know, this is not an antivirus but IMO, the sandbox protection model is the way to go. Once properly configured, Sandboxie = 0 malware infections and no system slowdowns. Briefly, Sandboxie is a virtual environment that traps all the malware inside it, preventing them from harming your PC.

If you choose this solution, make sure you understand how it works so please take your time to go though the website explanation as well as the tutorial.

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not really 'antivirus' software, but once you got 'the hang of it', you can do very well without AV software :) +1 – Molly7244 Sep 9 '09 at 18:00

I use Threatfire with Avira

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Panda Cloud Antivirus is free and it is unique whereby it scans your files out in the cloud instead of using up resources on your computer.

alt text

There is a good review here if you are interested.

CI [Collective Intelligence (CI) cloud] is also how Panda’s Cloud Antivirus lowers system resource usage. This is because all the protections reside within a distributed network of datacenters (or 'the cloud' if you will), which, in turn, absolves the need for the user's computer to crunch data and page through an endless amount of signatures to process potential Malware.

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Wow. That's amazing. How does the "Cloud" periodically scan all your exe's, dll's and cab's for infections, does it upload it all through your Internet connection? It sounds like a Panda marketer got ahold of a great new marketing term... Cloud! – kmarsh Sep 9 '09 at 15:41
Since they are storing the signatures in various data centers and not on the client's computer, I think the use of "Cloud" is appropriate. – Rob Allen Sep 9 '09 at 16:02
I suggest you don't install this until it's out of beta. It's not that it doesn't work but Panda CloudAV is nowhere as polished as Avast or MSE. – kai Sep 9 '09 at 17:17
While some are seeking every possible network performance improvements by even elimination cookies, in order to send as little data as required (like, I kind of doubt that querying the cloud for each file will use less resources than using a local signature database. The only real advantage I see might be a full up-to-date signature database. – Arjan Sep 10 '09 at 10:16

Free? Avast. I use this at home.

Not free? Vipre from Sunbelt Software. We use the enterprise edition of this at the office and it's been very easy to setup and doesn't slow down the machine.

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ESET Nod32 uses just 1,100k and i can run it along with xp pro on a pentium 2.

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1,100k of what? – Tom Wijsman Jul 13 '12 at 17:47

The lightest I have seen is Sophos, however it seems to be really targeted at corporate use.

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