NICGIGA
NICGIGA 2.5G Base-T PCIe Network Adapter
Bottom line: The NICGIGA 2.5G Base-T PCIe Network Adapter ($19.99 on Amazon as of 2026-10-06): Realtek RTL8125B chip delivers up to 2.5Gbps over a standard RJ45 port; main trade-off: PCIe only; will not fit legacy PCI slots in older boards.
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*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.
Pros & Cons
Pros
- ✓ Realtek RTL8125B chip delivers up to 2.5Gbps over a standard RJ45 port
- ✓ Backward compatible with 1Gbps and 100Mbps networks
- ✓ Fits any PCIe x1, x4, x8 or x16 slot
- ✓ Full-height and low-profile brackets both included
- ✓ Windows 10 recognizes it without a driver install; heat sink on the controller
Cons
- ✗ PCIe only; will not fit legacy PCI slots in older boards
- ✗ Needs a 2.5G switch or router to go beyond 1Gbps
- ✗ Win 11/8.1/7, macOS and Linux may need a driver from Realtek's site
- ✗ Single RJ45 port, so no dual-port or failover setup
Manufacturer description
The NICGIGA 2.5G Base-T PCIe Network Adapter adds a 2.5Gbps RJ45 Ethernet port to your desktop through a spare PCIe slot. It uses the Realtek RTL8125B controller, which runs up to 2.5 times faster than standard Gigabit Ethernet. That extra bandwidth helps with large downloads, game patches, NAS transfers and live streaming. The card is backward compatible with 1Gbps and 100Mbps networks, so it works on your current router and switches today. To go beyond 1Gbps, you need 2.5G-capable networking gear. It fits PCIe x1, x4, x8 and x16 slots. It does not work in older PCI slots, so check your…
SpecPicks Verdict
SpecPicks scored NICGIGA 2.5G Base-T PCIe Network Adapter using a rating × review-volume × price-fit model applied to published specs and reviews across the retro networking cards category. NICGIGA's retro networking cards lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.
Common buyer scenarios for retro networking cards of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.
Frequently Asked Questions
Will this card work in my motherboard's PCIe x16 slot?
Yes. The NICGIGA adapter works in PCIe x1, x4, x8 and x16 slots. It does not work in older PCI (non-Express) slots.
Do I need to install a driver?
Not on Windows 10, which recognizes the card without a driver. For Windows 11, 8.1, 8, 7, macOS and Linux, download the RTL8125B driver from Realtek's official website.
Will I get 2.5Gbps speeds on my existing router?
Only if your router or switch has 2.5G ports. The card is backward compatible with 1Gbps and 100Mbps, so on standard Gigabit gear it connects at 1Gbps.
Does it fit a small form factor or low-profile case?
Yes. It comes with both a standard full-height bracket and a low-profile bracket, so it fits desktops, workstations, servers and mini-tower cases.
What warranty and support does NICGIGA offer?
NICGIGA advertises lifetime technical support and says it responds within 24 hours. Check the product listing for current warranty terms.
Key Features
- [Super-fast 2.5Gbps Networking] High up to 2.5x-speed with Realtek RTL8125B chip, much faster data-transfer speeds for gaming, living broadcasts and downloads in bandwidth-demanding tasks.
- [Complete Compatibility] Seamless backward compatibility for 2.5Gbps/1Gbps/100Mbps, Support Windows11/10/8.1/8/7, MAC OS and Linux, no dirver needed on Windows10, easily download the driver in Realtek official website for other OS.
- [PCIe to 2.5G RJ45] This 2.5GBASE-T PCIe Network Adater convers a PCIe slot(X1/X4/X8/16) into a 2.5G RJ45 Ethernet Port. Note: Only work with PCIe slot, not for PCI slot.
- [Widely Use with Heat Sink]Comes with standard bracket and low-profile-bracket to meet the needs of different cases such as desktop, workstation, server, mini tower computer and so on. Excellent heat dissipation can reduce the temperature quickly and maintain the stability of network transmission.
- [Customer Service]Friendly service for lifetime technical supporte. If you encounter any problems, please contact us, our customer team will slove the problem for you within 24 hours.
Full Specifications
| UPC | 756166630512 |
|---|---|
| Brand | NICGIGA |
| Color | black |
| Item Weight | 0.09 Kilograms |
| Manufacturer | NICGIGA |
| Compatible Devices | Desktop |
| Data Link Protocol | Ethernet |
| Data Transfer Rate | 2500 Megabits Per Second |
| Hardware Interface | Ethernet, PCI |
| Product Dimensions | 3.94"L x 2.36"W x 0.79"H |
| Full listing title | NICGIGA 2.5G Base-T PCIe Network Adapter, Realtek RTL8125B 2.5Gbps/1Gbps/100Mbps PCI Express Gigabit Network Card Convert to Ethernet RJ45 LAN Port for Gaming/Office, Support Windows/Linux |
Ready to buy?
NICGIGA 2.5G Base-T PCIe Network Adapter, Realtek RTL8125B 2.5Gbps/1Gbps/100Mbps PCI Express Gigabit Network Card Convert to Ethernet RJ45 LAN Port for Gaming/Office, Support Windows/Linux is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.
*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.
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