Disable minifilter drivers for a RAM disk
4 posts
Hi,
Is there a way to disable all minifilter drivers for a RAM disk? Is it worth it? Should I expect increased performance by doing this?
Thanks in advance
You can't cleanly disable the whole minifilter stack per-volume. Minifilters decide whether to attach themselves, and the volume gets no veto. What you can do:
- See what's attached:
fltmc instances -v X:
- Detach a specific one:
fltmc detach <Filter> X:
The one that actually matters is antivirus. It's best handled by exclusion, for example Windows Defender can be configured to exclude specific disk letters.
The performance gain is going to be meaningful only for small-file / metadata-heavy workloads (e.g. builds, temp dirs), where AV per-IRP scanning is a large relative fraction of the near-instant RAM I/O. For big sequential I/O it's noise. Tradeoff: excluded data isn't scanned. So don't strip the stack - just exclude from AV, benchmark a small-file test, and keep it only if the numbers justify the security tradeoff.
Exciting news: RAM Filesystem is coming soon! 🚀
We have a new product RAM Filesystem coming, that sidesteps this entirely. Instead of a block device with NTFS on top (the classic RAM disk), it's a true in-kernel filesystem. It eliminates both the OS cache double-copy and the entire block storage stack, serving I/O directly from extents in the kernel.
Compared to conventional NTFS RAM disk on the same RAM:
- Unbuffered random 4K: +95-140%.
- Buffered I/O: up to +600-700% sequential and random 4K, because there's no cache or double-copy.
- Metadata: create ~5-7×, delete up to ~16× faster than NTFS.
So rather than fighting the filter stack on a RAM disk, RAM FS removes the storage-stack overhead at the source. The release is planned for late July or early August.
Thank you for your detailed response. The new product you mentioned sounds great! It addresses the question I posted in August 2023 about the Windows Cache and the double copy that occurred.
Is the SoftPerfect RAM Filesystem a product that will work with SoftPerfect RAM Disk? By that I mean, within the RAM Disk product, can I create a disk with FAT, exFAT, NTFS, or RAMFS filesystems?
I'm looking forward to the new product.
It will be a separate product rather than an additional file system option within the RAM Disk, as architecturally it's completely different and doesn't share any components with the RAM Disk. The RAM Disk will remain unchanged, supporting FAT, exFAT and NTFS, while the RAM Filesystem will support a single file system only: RAMFS.
Because RAMFS is a purpose-built file system, it can offer settings that aren't possible with standard file systems, such as configurable compression levels (None, Fast, Normal or Maximum). More importantly, its architecture is designed for performance, delivering around 5-7-times higher throughput for buffered I/O by eliminating the cache and block storage layers, and roughly doubled performance for small unbuffered I/O by avoiding the storage stack overhead.
If you wish, you will be able to install and use both products side-by-side without any conflicts.