Which security camera setup do you actually need?
Most PC builders approach security cameras the same way they approach a GPU: chase the biggest number on the box. With surveillance gear, though, resolution is only one part of image quality. The sensor size, lens aperture and bitrate matter just as much. Entry-tier cameras (typically 2MP to 4MP) use small sensors that gather little light, so at night the image shifts to grainy infrared with heavy noise reduction smearing detail. Sweet-spot cameras (4MP to 8MP) use larger sensors and faster lenses, which means a cleaner picture and often usable colour at night with a small supplementary light. Enthusiast gear adds varifocal motorised lenses, better on-camera AI, and proper wide dynamic range for backlit driveways.
Diminishing returns hit fast above 4K. A 4K camera with a tiny sensor and a slow lens can look worse after dark than a good 4MP unit. Resolution also only helps if the subject fills enough pixels, so a tighter field of view often beats more megapixels. Think about what each camera needs to identify: a face at the front door needs far more pixel density than a general view of the backyard.
Then there's the recording architecture. Wi-Fi cloud cameras are simple but depend on your upload bandwidth, subscriptions and the vendor's servers. PoE cameras feeding an NVR give you continuous recording, local storage and a single cable per camera for power and data. If you're already comfortable building PCs, a DIY NVR is the third option, and it's a very good one.
Upgrading and technical nuances
Codec choice changes your storage maths more than almost anything else. H.265 roughly halves the bitrate of H.264 at similar quality, so a 4MP stream might sit near 4 Mbps instead of 8. Run that across eight cameras recording continuously and you're writing roughly 350 GB a day, which is about 10 TB for a month. Smart codecs like H.265+ cut it further, but they can soften detail during motion, which is precisely when you want it sharp.
For a DIY NVR, the CPU matters less than people assume. Software like Frigate or Blue Iris leans on hardware video decoding, and Intel's integrated Quick Sync on current CPUs & Processors handles many simultaneous streams at very low power. A discrete Graphics Card / GPU only earns its place if you're running heavier AI object detection across many cameras. Pair that with a sensible Motherboard that has enough SATA ports for bulk drives, and 16GB of Desktop Memory is plenty for most home systems.
Storage splits into two jobs. Continuous footage belongs on surveillance-rated hard drives such as WD Purple or Seagate SkyHawk, which are tuned for sustained sequential writes across many streams and have firmware that avoids the error-recovery stalls that drop frames. Use a Solid State Drive (SSD) like a Samsung 990 or Crucial T500 for the operating system, database and event clips, since constant small writes and random lookups suit flash. Don't use cheap QLC drives for 24/7 recording. Their endurance ratings and sustained write behaviour fall off badly once the SLC cache runs out.
PoE standards are a real compatibility trap. Most cameras run on 802.3af (15.4W), but PTZ units and cameras with heaters or IR illuminators may need 802.3at (30W). Check the switch's total PoE budget, not just per-port ratings. A 60W budget won't run eight 8W cameras comfortably once you factor in cold-start draw. Quality Networking gear matters here, and the TP-Link range, including its VIGI camera line and PoE switches, is a solid mainstream option that keeps the ecosystem simple.
Practical things to check before buying
Cabling comes first. Use solid-copper Cat5e or Cat6 for PoE runs. Copper-clad aluminium cable looks identical and costs less, but it has higher resistance, runs hotter and often fails at distance. Proper Cables & Connectors and weatherproof glands make a bigger difference to long-term reliability than most people expect. Keep runs under 100 metres and avoid routing beside mains wiring.
If you're building the NVR, the chassis needs to suit a machine running 24/7. A Computer Case with several 3.5-inch bays and good front airflow keeps hard drives cooler, and drives running consistently above 45°C die sooner. Quiet, fluid-dynamic-bearing fans from Fans, Heatsinks & Cooling last longer in continuous operation than cheap sleeve-bearing units. A modest tower cooler from CPU Cooling keeps temperatures steady without noise.
Power supply quality counts because this machine never turns off. A 450W to 550W unit from the Power Supplies range, such as a Seasonic Focus or Corsair RMx, has the efficiency and capacitor quality to idle for years. If you want a straightforward standard unit, check the ATX Power Supply options. Add a small UPS so a brownout doesn't corrupt your recording database. If you want a prebuilt box instead, browse Computers for compact systems that suit the job.
For viewing, a Monitor running a multi-camera grid benefits from a 4K panel with decent pixel density, but refresh rate is irrelevant since camera streams typically run at 15 to 25 fps.
Finally, check the camera's field of view, IP66 or higher weather rating, and whether it supports ONVIF so it plays nicely with third-party NVR software.
Brands and local warranty
Reputable names to look for include Reolink, TP-Link VIGI, Ubiquiti UniFi Protect, Axis for commercial-grade work, and Swann or Eufy for simpler consumer setups. Be aware that some Hikvision and Dahua products have been removed from Australian government sites over security concerns, so research firmware support and update history before buying them.
Local warranty matters because cameras live outdoors and fail in ways that aren't obvious, such as condensation, IR cut-filter faults or PoE port damage. Under Australian Consumer Law you have guarantees that apply regardless of the manufacturer's stated warranty, but enforcing them is far smoother with a local retailer and a supplier that has an Australian presence. Grey imports often have no local support, and firmware or power adapters may be region-specific.
Frequently asked questions
Q: How much storage do I need for a home security camera system?
Multiply each camera's bitrate by the number of cameras and your retention days. Eight 4MP H.265 cameras at about 4 Mbps recording continuously need roughly 10 TB for 30 days. Motion-only recording cuts that substantially.
Q: Is PoE better than Wi-Fi for security cameras?
For reliability, yes. PoE delivers stable bandwidth and power over one cable, with no signal drops or battery changes. Wi-Fi is fine for a single indoor camera or places you can't cable.
Q: Can I use a normal PC as an NVR?
Yes. A low-power modern CPU with hardware video decoding handles many streams, as long as you add surveillance-rated drives and a decent PoE switch. You rarely need a dedicated GPU unless you're running heavy AI detection.
Q: Is 4K always better than 4MP?
Not necessarily. A 4K camera with a small sensor and slow lens can lose to a good 4MP unit at night. It also doubles your storage demands, so only go 4K where you need the extra detail.
Q: Do I need a surveillance hard drive, or will any drive work?
Any drive will record, but surveillance drives handle continuous multi-stream writes and avoid long error-recovery stalls that cause dropped frames. For 24/7 recording, they're worth the small premium.
